2012年05月14日

报告题目：Representations of binary quadratic forms as Lambert series
报告人：Toh Pee Choon 博士 （新加坡南洋理工大学）
报告时间：2012.5.17 上午9：30-10:30
报告地点：闵行校区数学楼102报告厅
摘要：Classical algebraic number theory allows us to write certain Lambert series as a sum of theta series associated to classes of binary quadratic forms. We will recall how this is done and then give an inversion process to isolate some of these theta series and represent them by a linear combination of Lambert series. We will also demonstrate how this method allows us to prove some recent conjectures of Ray Melham involving sums of polygonal numbers。

2012年05月11日

Title: Ricci flow and analysis

Speaker: Professor Xiaodong Cao (Cornell University)

Lecture 1:
Time: 10:00-11:30 May 7, 2012
Room: Room 102, Mathematics Department

Lecture 2:
Time: 10:00-11:30 May 9, 2012
Room: Room 102, Mathematics Department

Lecture 3:
Time: 13:00-14:30 May 10, 2012
Room: Room 102, Mathematics Department

Lecture 4:
Time: 10:00-11:30 May 21, 2012
Room: Room 102, Mathematics Department

Lecture 5:
Time: 10:00-11:30 May 23, 2012
Room: Room 102, Mathematics Department

Abstract:
In this series of lectures, we will start with a brief introduction of
the Ricci flow, by surveying some well-known theorems and fundamental
techniques in this field. Then we will discuss formation of
singularities, ancient solutions and Ricci solitons. Finally we will
focus on some analytic aspects of the Ricci flow, such as Harnack
inequalities, curvature pinching estimate, heat kernel estimate and
their applications.

2012年05月10日

报告题目：Smoothness and Long-time Behavior of the Spreading Front Determined by a Nonlinear Free Boundary Problem
报告人： Prof. Yihong Du (University of New England, Australia)
时间：2012年5月15日（周二） 15:30-16:30
地点：闵行数学楼102报告厅

Abstract:
We consider the spreading of species governed by a free boundary model. In
one space dimension and in the radially symmetric case with a logistic
nonlinear term, it is known that this model exhibits a spreading-vanishing
dichotomy. In this talk we discuss the non-radially symmetric case
with more general nonlinearities. By establishing suitable regularity of
the free boundary, we show that the spreading-vanishing dichotomy still
holds. Moreover, when spreading happens, the normalized free boundary
approaches the unit sphere as time goes to infinity. For logistic
nonlinearity we obtain a complete extension of the previous results
in the radially symmetric case to the general case. This is joint work
with Hiroshi Matano and Kelei Wang.

2012年05月10日

报告题目： Fractional Diffusion Equations and Their Fast Solution
报 告 人： 王 宏 教授
Department of Mathematics, University of South Carolina

时 间： 2012年5月13日下午：1:30-2:30
地 点： 中山北路校区理科大楼A座1414室

报告简介： Fractional diffusion equations model phenomena exhibiting anomalous diffusion that cannot be modeled accurately by the second-order diffusion equations. Because of the nonlocal property of fractional differential operators, the numerical methods for fractional diffusion equations often generate dense or even full coefficient matrices. Consequently, these methods have excessive computational work and memory requirement.
In this talk we go over the fractional diffusion equations and present a fast numerical method for space-fractional diffusion equations. The method has demonstrated significant computational and memory benefit, which shows the utility of the method.

2012年04月11日

数学系-偏微分方程中心联合讨论班--PDE SEMINAR

2012年04月11日

数学系-偏微分方程中心联合讨论班--POSTDOC SEMINAR

2012年04月11日

学术报告（微分动力系统）

时间：2012年4月12日（星期四）下午3:00--4:30
地点：闵行校区数学楼102报告厅
报告人：韩茂安 教授,（上海师范大学）
报告题目：中心焦点判定与Hopf 分支问题

摘要：中心判定问题和Hopf分支有密切关系，它们都是微分方程定性理论的经典内容。本报告主要介绍研究中心判定问题和Hopf分支的主要方法和思路，特别介绍本人学习和教授这一内容的理解和体会。

2012年03月19日

时间：2012年3月23日（星期五）下午1:30--3:30
地点：闵行校区第四教学楼206教室
报告人：谢春景 博士, 特别研究员（上海交通大学）
报告题目：Some recent progress on subsonic Euler flows

摘要：In this talk, we will discuss some recent progress on subsonic
Euler flows in nozzles and on the half plane. This include the existence and stability of subsonic Euler flows in two dimensional non-smooth infinitely long nozzles, existence of subsonic Euler flows in three dimensional bounded nozzles, and global solutions of subsonic Euler flows in half plane with particular application to subsonic
Euler flows past a symmetric body. The analysis is based on new formulations for steady Euler equations, and a priori estimates for elliptic equations and transport equations in various situations.

These results are joint work with Chao Chen, Lili Du.

2012年03月13日

学术报告（偏微分方程，流体力学）

时间：2012年3月16日（星期五）下午1:30--3:30

地点：闵行校区第四教学楼206教室

报告人：胡殿 博士（上海大学）

报告题目：STABILITY OF THE E-H TYPE REGULAR REFRACTION OF SHOCKS ON THE
INTERFACE BETWEEN TWO MEDIA

摘要：In this report, I will give some results about the boundary value
problem for the Lavrentiev-Bitsadze equation and the application of it
in the study of E-H type wave structure.

2012年03月12日

报告题目：On the Foundations of Murray-von Neumann Algebras
报告人：Richard V. Kadison 教授
时 间： 2012年3月28日（星期三）上午9：30
地 点： 普陀校区理科大楼A510室
摘 要： An introduction to a newly developed subject (though, given a powerful beginning in 1937 by Murray and von Neumann) involving families of unbounded operators affiliated with finite von Neumann algebras and some of the basics of quantum mechanics.

2012年03月12日

报告题目：The Origins – an Introduction to Operator Algebras
报告人：Richard V. Kadison 教授
时 间： 2012年3月26日（星期一）上午10：00
地 点： 普陀校区理科大楼A510室
摘 要： An introduction to the theory of operator algebras with a mixture of historical and technical discussion.

2012年03月08日

报告题目：Orbit configuration spaces of equivariant manifolds

报告人：吕志 教授 复旦大学数学学院

地点：中山北路校区理科大楼A1414室

时间：2012年3月10日 14:00

2012年03月02日

数学系-偏微分方程中心联合讨论班
题目: Introduction to functional differential equations
报告人: 毕平副教授(华东师大数学系)
时间: 2012年3月13日(周二)下午13:00-15:00
地点: 闵行校区行政楼12楼偏微分方程中心1202报告厅
摘要:Functional differential equations are important in many areas of engineering and science. The aim of this talk is to give a brief introduction on the theory and applications of FDEs.

First, various examples of functional differential equations arising in real life problems are presented. The possible effects of time delays on some of these systems are briefly discussed, which show the small delays can have large influences. Secondly, the classification and the basic theory of functional differential equations are presented. All these results are prepared for the qualitative theory and bifurcation theory of functional differential equations in infinite dimension.

2012年03月02日

数学系---偏微分方程中心联合讨论班
题目：Two species competition models with small diffusion rates
报告人：李敬宇 博士（华师大PDE中心博士后）
时间：2012年3月6日(周二)下午13:00-15:00
地点：闵行校区行政楼12楼偏微分方程中心1202报告厅
摘要： In this seminar, I will discuss some known results, as well as the related methods, on the effect of small diffusion
rates for the two species competition models. I will mainly focus on the existence and stability of the coexistence steady states. For details one can refer to
the interesting paper of Hutson, Lou and Mischaikow published in the Journal of Differential Equations in 2005.

2012年02月27日

数学系-偏微分方程中心联合讨论班
题 目: Entire Solutions of the KPP Equation
报告人: 王丽娜 博士（华师大PDE中心博士后）
时 间: 2012年2月21日（周二）下午13: 00-15:00
地 点: 闵行校区行政楼12楼偏微分方程中心1202报告厅
摘 要： In this talk, I would like to introduce F. Hamel and N. Nadirashvili’s results on entire solutions of the KPP equation, which is published on “Comm. Pure Appl. Math”. The authors deal with the solutions defined for all time of the KPP equation ${{u}_{t}}={{u}_{xx}}+f(u)$, $0<$$u(x,t)<1$, $(x,t)\in {{\mathbb{R}}^{2}}$, where $f$ is a KPP-type nonlinearity defined in $[0,1]$: $f(0)=f(1)=0$, ${{f}^{'}}(0)>0$, ${{f}^{'}}(1)<0$, $f>0$ in $(0,1)$, and ${{f}^{'}}(s)\le {{f}^{'}}(0)$ in $[0,1]$. This equation admits infinitely many traveling-wave-type solutions, increasing or decreasing in $x$. It also admits solutions that depend only on $t$. In this paper, the authors build four other manifolds of solutions: One is 5-dimensional, one is 4-dimensional, and two are 3-dimensional. Some of these new solutions are obtained by considering two traveling waves that come from both sides of the real axis and mix. Furthermore, the traveling wave solutions are on the boundary of these four manifolds.

2012年02月27日

题目：Traveling Fronts and Entire Solutions of the Fisher-KPP Equation in $\mathbb{R}^N$
报告人：王丽娜 博士（华师大PDE中心博士后）
时间：2012年2月28日(周二)下午 13:00-15:00
地点：行政楼12楼偏微分方程中心1202报告厅
摘要：
In this talk, I would like to introduce the main results on entire solutions of the Fisher-KPP equation in $\mathbb{R}^N$, which is written by F. Hamel and N. Nadirashvili and published on "Arch. Rational Mech. Anal" .

$u_t=\Delta u+f(u),$ $0<$$u(x,t)<1,$ $x\in \mathbb{R}^N,$ $t\in \mathbb{R}$

where $f$ is a $C^2$ concave function on $[0,1]$ such that $f(0)=f(1)=0$ and $f>0$ on $(0,1)$.
In this talk, I will introduce the existence of an infinite-dimensional manifold of entire solutions, infinite-dimensional manifolds of non-planar traveling fronts and radial solutions.

2012年02月13日

题目：Some analytic methods in asymptotic combinatorial enumerations.
时间：2012年2月15日（星期三）上午10:00-11:00
地点：闵行数学楼102报告厅
报告人：Prof. Zhicheng Gao, Carleton University, Ottawa, Canada.

摘要:
This talk covers some analytic methods which are used frequently in the study of large combinatorial structures. They include Darboux’s Lemma, Flajolet-Odlyzko’s Transfer Theorems, Central and Local Limit Theorems.Some well-known combinatorial structures such as integer compositions,permutations, polynomials over finite fields, and graphs will be used to illustrate these analytic methods.

2012年01月09日

时间：2012年1月9日 上午10:00-11:00

地点：闵行数学楼126室

报告人： 蒋云平 教授 （纽约城市大学，Transactions of AMS 与 Memories of AMS 编委，中科院百人计划获得者）

题目：混沌动力系统与复数的动态结构

摘要：混沌是动力系统中的一个非常有趣的现象。即使在最简单的复二次多项式系统中，这些 混沌现象不仅存在而且非常的复杂。近几年中许多复分析中的工具被用在研究这些非常复杂的混沌现象。这些工具包括正规族理论 (normal family theory)，拟共形映照理论 (quasiconformal mapping theorey)，Teichmuller空间理论等等。同时这也推动了这些工具的进一步的发展。在这个演讲中，我将从复数在复二次多项式迭代系统中的结构谈起。由此引进这些混沌现象以及混沌动力系统发展的简单历史。
进一步的，我将讨论复动力系统中的一些重要问题以及最近的发展。同时我也将讨论我们在这一发展中的工作。

2012年01月04日

时间: 2012-01-05 10:30

地点：闵行数学楼102报告厅

Title: Combinatorial codes--A survey

Abstract: Combinatorial designs have close connections with coding theory. In this talk, I will give a survey on combinatorial codes which were studied in the combinatorial community of China. These include: optical orthogonal codes, conflict-avoiding codes, impulse radio sequences, constant weight codes, constant composition codes, perfect deletion-correcting codes, frequency hopping sequences, comma-free codes etc. Several open problems are also mentioned.

报告人简介:

葛根年，教育部“长江学者奖励计划”特聘教授、国家杰出青年科学基金获得者、“新世纪百千万人才工程”国家级人选、教育部“新世纪优秀人才支持计划”入选者、浙江省“新世纪151人才工程”第一层次培养人员。

长期从事组合设计理论及其应用研究，具体内容涉及组合设计理论、编码密码学、计算机科学、生物信息学和统计学等领域。现任中国组合数学与图论学会副理事长、国际组合数学及其应用协会Fellow。目前受邀担任国际组合设计界权威SCI期刊《Journal of Combinatorial Designs》及《The Open Mathematics Journal》、《International Journal of Combinatorics》、《Advances and Applications in Discrete Mathematics》四个国际期刊的编委。曾获得由国际组合数学及其应用协会颁发的—“Hall Medal”、第十一届中国青年科技奖、教育部高等学校科学技术奖自然科学二等奖、第八届浙江省青年科技奖、浙江省高等学校科研成果一等奖（2项）、第七届全国统计科学研究优秀成果二等奖。

2011年12月31日

数学系-偏微分方程中心联合讨论班
题 目: On the global existence and finite time blow-up of shadow systems
报告人: 李芳 博士（华师大PDE中心博士后）
时 间: 2011年12月31日（周六）下午13: 00-16:00
地 点: 闵行校区行政楼12楼偏微分方程中心1202报告厅
摘 要：Shadow systems are often used to approximate reaction–diffusion systems when one of the diffusion rates is large. In this talk, we discuss the global existence and blow-up phenomena for shadow systems. Our results show that even for these fundamental aspects, there are serious discrepancies between the dynamics of the reaction–diffusion systems and that of their corresponding shadow systems.

2011年12月29日

曹锡华数学论坛

清华大学博士后（加拿大Universite de Sherbrooke博士）
的学术报告

时间：2012年元月9日（星期一）下午3:00--5:00

地点：闵行校区数学楼102报告厅

报告1： On the cluster category of a marked surface
This is a joint work with Thomas Brustle. We study the cluster category C(S,M) of a marked surface (S,M). We explicitly describe the indecomposable objects in C(S,M) as homotopy classes of curves in (S,M) and one-parameter families related to non-contractible closed curves in (S,M). Moreover, we describe the Auslander–Reiten structure of the category in geometric terms and show that the objects without self-extensions in C(S,M) correspond to curves in (S,M) without self-intersections.

报告2：On the cluster algebra of a marked surface
This is a joint work with Thomas Brustle. We study the cluster algebra A(S,M) of a marked surface (S,M). We introduce Schiffler-Thomas’ expansion formula by an example. Based on the geometric description of the indecomposable objects of the cluster category C(S,M), we show the coincidence of Schiffler-Thomas’ expansion formula and the cluster character defined by Palu.

欢迎数学系教师和研究生光临！

2011年12月27日

报 告 人: Cooper教授 (新西兰Massey大学)
时间：2011/12/30(周五)， 上午10点半-11点半
地点：闵行校区数学楼102报告厅
报告题目: Sporadic sequences and modular forms

报告内容：Just over ten years ago D. Zagier conducted an extensive computer search for integers
$a$, $b$ and $c$ such that the sequence $u_{n}$ defined by
$$
(n+1)^{2}u_{n+1}=(an^{2}+an+b)u_{n}+cn^{2}u_{n-1},\quad u_{0}=1,\;\;u_{-1}=0
$$
produces only integer values. Only six nontrivial examples were found and it is conjectured that
there are no others.

This talk is about a recent search for integral valued sequences defined by
$$
(n+1)^{3}u_{n+1}=(2n+1)(an^{2}+an+b)u_{n}+n(cn^{2}+d)u_{n-1}, \quad u_{0}=1,\;\;u_{-1}=0.
$$
Three nontrivial examples that were found are
$$
(a,b,c,d)=(13,4,27,-3),\quad (6,2,64,-4)\quad\mbox{and}\quad (14,6,-192,12).
$$
These sequences have some remarkable properties.
For example, there are explicit formulas for the terms in each sequence as sums of binomial coefficients.
There are some interesting divisibility properties that will be stated as conjectures.
Moreover, the sequences turn out to be connected with modular forms of levels $7$, $10$ and $18$, respectively.

These results, the experimental procedure that led to their discovery, and the reasons for doing the search
will be described.

2011年12月27日

报 告 人: 王伟强教授 (美国Virginia大学)
时间：2012/01/10(周二)， 上午10点-11点
地点：闵行校区数学楼102报告厅
报告题目: Spin coinvariant algebras and spin fake degrees for Weyl groups

报告内容：The coinvariant algebra of a Weyl group W is a graded regular representation of W. The graded multiplicities of simple W-modules in a coinvariant algebra are known as fake degrees and have been computed by Lusztig and others. We formulate the notion of spin coinvariant algebra for a double cover $\tilde{W}$ of every Weyl group W, and determine all the spin fake degrees, i.e., the graded multiplicity of spin simple modules of $\tilde{W}$. This talk is based on the Virginia dissertation of Constance Baltera.

2011年12月22日

数学系-偏微分方程中心联合讨论班
题 目: On “Regularity of the nodal set of segregated critical configurations under a weak reflection law” (II)
报告人: 刘 单 博士（华师大偏微分方程中心博士后）
时 间: 2011年12月27日（周二）下午13: 00-15:00
地 点: 闵行校区行政楼12楼偏微分方程中心1202报告厅
摘 要：In this talk, I would like to introduce H. Tavares and S. Terracini’s results on regularity of the nodal set, which is published in “Calculus of Variations of PDEs” in 2010. The authors deal with a class of Lipschitz vector functions whose components are nonnegative, disjointly supported and verify an elliptic equation on each support. Under a weak formulation of a reflection law, they prove that the nodal set is a collection of C^{1,\alpha} hyper-surfaces up to a residual set with small Hausdorff dimension. Moreover, I will talk about some applications in this paper, such as to the asymptotic limits of reaction-diffusion systems with strong competition interactions.

2011年12月16日

题目(Title)：Surfaces moving by powers of Gauss curvature
报告人： 陈旭忠 博士后 （清华大学）
地点： 闵行数学系102报告厅
时间： 12月21日（周三） 13：00-14：00
摘要(Abstract)：
In this talk, we will consider surfaces moving by powers of Gauss curvature in three-dimensional Euclidean space. We prove that strictly convex surfaces moving by $K^{\alpha/2}$ become spherical as they contract to points, provided $\alpha$ lies in the range $[1,2]$. In the process we provide a natural candidate for a curvature pinching quantity for surfaces moving by arbitrary functions of curvature, by finding a quantity conserved by the reaction terms in the evolution of curvature.

2011年12月15日

数学系-偏微分方程中心联合讨论班
题 目: On “Regularity of the nodal set of segregated critical configurations under a weak reflection law”
报告人: 刘 单 博士（华师大偏微分方程中心博士后）
时 间: 2011年12月20日（周二）下午13: 00-15:00
地 点: 闵行校区行政楼12楼偏微分方程中心1202报告厅
摘 要：In this talk, I would like to introduce H. Tavares and S. Terracini’s results on regularity of the nodal set, which is published in “Calculus of Variations of PDEs” in 2010. The authors deal with a class of Lipschitz vector functions whose components are nonnegative, disjointly supported and verify an elliptic equation on each support. Under a weak formulation of a reflection law, they prove that the nodal set is a collection of C^{1,\alpha} hyper-surfaces up to a residual set with small Hausdorff dimension. Moreover, I will talk about some applications in this paper, such as to the asymptotic limits of reaction-diffusion systems with strong competition interactions.

2011年12月15日

报告人：吴忠涛博士， 美国加州理工大学

报告题目：Smooth Poincare conjecture

时间：2011年12月15日下午1:00-2:30

地点：闵行数学楼102室

2011年12月12日

林华新教授60周年校庆学术报告

题 目： 百年辛亥话数学
报告人： 林华新
时 间： 2011年12月14日下午2：00
地 点： 闵行校区图书馆裙楼一层多功能学术报告厅
报告人简介：
林华新，教授、博士生导师，教育部长江学者讲座教授，国家“千人计划”入选人。

报告内容简介：
百年辛亥话数学， 话从二个酉矩阵谈起。 从线性代数到非交换拓朴学--C*-代数。 回顾几千年来中国数学的发展。 兼谈甲申辛亥---一个数学人的视角。

期待您的参加！

2011年12月12日

题目：BLM realization of $\mathcal U(\widehat{\frak{gl}}_n)$.
时间：2011年12月13日下午4:30-5:30
地点：闵行数学楼102报告厅
报告人：付强 教授 （同济大学）
摘要：We will discuss the BLM realization of the universal enveloping algebra $\mathcal U(\widehat{\frak{gl}}_n)$ of the loop algebra $\widehat{\frak{gl}}_n$. This result is taken from the last chapter in [Bangming Deng, Jie Du and Qiang Fu, A Double Hall Algebra Approach to Affine Quantum Schur--Weyl Theory, accepted by London Mathematical Society Lecture Note Series].

2011年12月08日

数学系-偏微分方程中心联合讨论班
题 目: Existence of standing waves of nonlinear Schrodinger equations with potentials vanishing at infinity
报告人: Ohsang Kwon 博士（华师大偏微分方程中心博士后）
时 间: 2011年12月13日（周二）下午13: 00-15:00
地 点: 闵行校区行政楼12楼偏微分方程中心1202报告厅
摘 要: In this talk, we prove the existence of bump solutions which concentrate around positive critical points of potential V vanishing at
infinity.

2011年12月07日

曹锡华数学论坛

题目：The converse of Glauberman's ZJ-theorem
时间：2011年12月19日（星期一）下午3:00
地点：数学楼报告厅（102）
报告人：Prof. Jianbei An （University of Auckland, New Zealand）

摘要:
Let $G$ be finite group, $p$ an odd prime factor of the order $|G|$ of $G$ and $S$ a Sylow $p$-subgroup of $G$. Glauberman's ZJ-theorem states that if $G$ has no subquotient isomorphic to a quodratic group, then $N(Z(J(S)))$ controls $p$-fusion of $G$, where the quodratic group is the semidirect product $p^2{:}SL_2(p)$ of elementary abelian group $p*2$ and the special linear group $SL_2(p)$ (with natural action of $SL_2(p)$ on $p^2$), and $Z(J(S))$ is the center of the Thompson subgroup $J(S)$ of $S$.

Glauberman's ZJ-theorem is one of the very important theorems in the finite group theory.

In this talk I'll discuss the converse of Glauberman's theorem. The talk is based on my two research papers.

2011年12月06日

题目：国际数学大师陈省身与芬斯勒流形
报告人： 莫小欢（北京大学数学学院教授）
时间： 2011年12月10日（周六）下午 13:00－14:00
地点：闵行校区数学系102报告厅

报告摘要：正值陈省身诞辰一百周年，我们回顾微分几何大师陈省身教授，感受陈先生生前所提倡的黎曼－芬斯勒几何之过去和现在。此报告为通俗报告，欢迎广大本科生和研究生参加。

2011年12月05日

题目： Introduction of the graduateschool of Information Science and Technology

报告人: Susumu Ariki 教授，MasaakiWada 教授

时间: 2011年12月9日，下午2：30

地点: 闵行校区数学楼102报告厅

2011年12月05日

题目： Visualizing once-puncturedtorus groups

报告人: Masaaki Wada 教授

时间: 2011年12月9日，下午1：30

地点: 闵行校区数学楼102报告厅

摘要： In a joint project with H. Akiyoshi, M. Sakuma and Y. Yamashita, while studying Troels Jorgensen's theoryon once-punctured torus groups, I wrote a computer program named OPTi.
http://delta.math.sci.osaka-u.ac.jp/OPTi/
Since I made it available on the internet, the program has been popular among the researchers of hyperbolic geometry and Kleinian groups. I will demonstrate the program and explain the mathematical background.

2011年12月05日

题目：Cosmetic surgeries on knots in $S^3$
报告人 倪毅教授（美国加州理工学院）
时间：2011年12月7日 下午 2:00-3:00
地点：中山北路理科大楼1414室

摘要 Two Dehn surgeries on a knot are called purely cosmetic, if they yield
manifolds that are homeomorphic as oriented manifolds. I will talk about
necessary conditions for the existence of purely cosmetic surgeries on
knots in $S^3$. In particular, the two surgery slopes must be the opposite
of each other. The proof uses a surgery formula for the correction terms
in Heegaard Floer homology. This is joint work with Zhongtao Wu.

2011年12月05日

题目： On knot invariants
报告人： 杨志青 教授（大连理工大学）
时间：2011年12月6日 上午 9:40-11:30
地点：闵行数学楼102室

摘要 The speaker will introduce a new knot inveriant developed by himself from the views of algebra and diagram.

2011年12月05日

数学系-偏微分方程中心联合讨论班
题 目: Nonexistence of Positive Solutions of Nonlinear Elliptic Systems with Potentials Vanishing at Infinity
报告人: Ohsang Kwon 博士（华师大偏微分方程中心博士后）
时 间: 2011年12月6日（周二）下午13: 00-15:00
地 点: 闵行校区行政楼12楼偏微分方程中心1202报告厅
摘 要：In this talk, we study the nonexistence of positive solutions for nonlinear elliptic systems with potentials vanishing at infinity, and establish the optimal vanishing order of potentials for the nonexistence of positive supersolutions in exterior domains.

2011年11月30日

报告：Circular Coloring and Periodic Scheduling
报告人： 叶鸿国 教授
（台湾中央大学数学系）
时间：2011年12月1号（周四）下午14:00-15:00
地点：华东师大闵行校区数学系102报告厅

2011年11月30日

报告：Nullity, maximum nullity and universally optimal matrix of graphs
报告人： 叶鸿国 教授
（台湾中央大学数学系）
时间：2011年12月1号（周四）上午10:00-11:00
地点：华东师大闵行校区数学系102报告厅

2011年11月25日

题目： On Sinc Discretization and Banded Preconditioning for Linear Third-Order ODEs
报告人： 白中治 研究员（中国科学院）
时间： 2011年11月28日（周一）下午 13:00－14:00
地点：闵行校区数学系102报告厅

报告摘要：Some draining or coating fluid-flow problems and problems concerning the flow of thin films of viscous fluid with a free surface can be described by third-order ordinary differential equations. In this talk, we solve the boundary value problems of such equations by sinc discretization and prove that the discrete solutions converge to the true solutions of the ordinary differential equations exponentially. The discrete solution is determined by a linear system with the coefficient matrix being a combination of Toeplitz and diagonal matrices. The system can be effectively solved by Krylov subspace iteration methods such as GMRES preconditioned by banded matrices. We demonstrate that the eigenvalues of the preconditioned matrix are uniformly bounded within a rectangle on the complex plane independent of the size of the linear system. Numerical examples are given to illustrate the effective performance of our method.

2011年11月24日

数学系-偏微分方程中心联合讨论班
题目：Asymptotic Behavior of Solution to a Chemotaxis Model with Volume-filling Effect
报告人：张艳艳 讲师（华东师大数学系）
时间：2011年11月29日（周二）下午13:00-15:00
地点：闵行校区行政楼12楼偏微分方程中心1202报告厅
摘要：In this paper, a 1-d quasilinear nonuniform parabolic chemotaxis model with volume filling effect is studied. We prove that the solution is uniformly bounded in time. Then we indicate the global solution’s existence, uniqueness and smoothness by Amann’s theory. What’s more, with the help of a suitable non-smooth Simon– Lojasiewicz approach, we obtain the results on convergence to equilibrium and the convergence rate.

2011年11月22日

题目：课题研究与论文写作技巧
时间： 2011年11月24日（星期四）下午15:00—16:40
地 点：闵行校区数学系129会议厅
报告人：韩茂安 教授（上海师范大学）
摘 要：报告人根据个人经历谈谈对课题研究与论文写作技巧的认识和体会。

2011年11月22日

题目：Knotted Periodic Orbits and Chaotic Behavior of a Class of Three-Dimensional Flows
时间： 2011年11月24日（星期四）下午15:00—16:40
地 点：闵行校区数学系129会议厅
报告人：李继彬 教授（浙江师范大学，昆明理工大学）
摘 要：Cconsiders a class of three-dimensional systems constructed by rotating some planar symmetric polynomial vector fields. It shows that this class of systems has infinitely many distinct types of knotted periodic orbits, which lie on a family of invariant torus. For two three-dimensional systems, exact explicit parametric representations of the knotted periodic orbits are given. For their perturbed systems, the chaotic behavior is discussed by using two different methods.

2011年11月22日

报告题目：Persistence and Non-persistence of Mutualism System with Stochastic Perturbation
演讲人：将达清 教授 （东北师范大学）
时间：2011年11月22日（星期二）上午10:15—11:05
地点：闵行校区四教217室

摘要：
In this talk, we consider a n-species Lotka-Volterra mutualism system with stochastic perturbation. Sufficient criteria for persistence in mean and stationary distribution of the system are established. Besides, we show the large white noise will make the system non-persistent. Finally, we illustrate the dynamic behavior of the system with n=3 and their approximations via a range of numerical experiments.

2011年11月17日

数学系-偏微分方程中心联合讨论班
题目：On Phase-Separation Model: Asymptotic and Qualitative Properties
报告人：赵纯奕 讲师（华东师大数学系）
时间：2011年11月22日（周二）下午13:00-15:00
地点：闵行校区行政楼12楼偏微分方程中心1202报告厅
摘要：We study bound state solutions of a class of two-component nonlinear elliptic systems with a large parameter tending to infinity. The large parameter giving strong inter-component repulsion induces phase separation and forms segregated nodal domains divided by an interface. To see the pro le of bound state solutions near the interface, we prove the uniform Lipschitz continuity of bound state solutions when the spatial dimension N = 1. Furthermore, we show the blow-up nonlinear elliptic system having unbounded solutions with symmetry and monotonicity.

2011年11月11日

数学系-偏微分方程中心联合讨论班
题 目: Exponential Stability of Large-Amplitude Traveling Fronts for Quasi-linear Relaxation Systems with Diffusion（II）
报告人: 王丽娜 博士（华师大PDE中心博士后）
时 间: 2011年11月15日（周二）下午13: 00-15:00
地 点: 闵行校区行政楼12楼偏微分方程中心1202报告厅
摘 要：This talk is concerned with the stability of traveling front solutions for 2×2 quasi-linear relaxation systems with small diffusion rate. By special Evans function estimates, detailed spectral analysis and C_0 semigroup theories, we prove that all the non-degenerate waves for semi-linear relaxation systems are locally exponentially stable in some exponentially weighted spaces. We also obtain the linear exponential stability of the non-degenerate waves for quasi-linear relaxation systems, where the wave strengths can be large.

2011年11月08日

学术报告
报告题目：Strong Edge-Coloring on Cubic Halin Graphs
报告人： Professor Daphene Liu
（California State University, Los Angeles , USA）
时间：2011年11月11号（周五）下午3:00-4:00
地点：华东师大闵行校区数学系102报告厅
Abstrast: A strong edge-coloring of a graph $G$ is a function that assigns to each edge with a color such thattwo edges within distance two apart must receive different colors. The minimum number of colors used inastrong edge-coloring is the strong chromatic index of $G$. In thistalk, we show that the strong chromatic index of a cubic Halin graph,
other than two special graphs, is $6$ or $7$, confirming a conjecture of Shiu and Tam. Then we discuss which cubic Halin graphs have strong chromatic index 6. Along the process, we disprove a conjecture by Shiu, Lam and Tam that a cubic Halin graph with the characteristic tree a caterpillar of odd leaves is $6$.
This talk includes joint works with Professor Ko-Wei Lih and with Professor Gerard Jennhwa Chang.

欢迎感兴趣的师生参加！

2011年11月07日

时间: 2011年11月7日 14:00
地点： 数学楼127室
报告人：Dr. Zhao Tiehong (赵铁洪 博士, 巴黎第六大学)
Institut de Mathématiques de Jusseiu
Université Pierre et Marie Curie
4, place Jussieu
F-75252 Paris, France

Title: Geometry of complex hyperbolic lattices

Abstract: In this talk, we review briefly the real hyperbolic geometry and
introduce the analogue definition of complex hyperbolic geometry,
which is the generalization of Riemann surface of hyperbolic type to
higher dimension. We constructed some fundamental domains for lattices
of PU(2,1) in complex hyperbolic space.

2011年11月04日

数学系-偏微分方程中心联合讨论班
题 目: Exponential Stability of Large-Amplitude Traveling Fronts for Quasi-linear Relaxation Systems with Diffusion.
报告人: 王丽娜 博士（华师大PDE中心博士后）
时 间: 2011年11月8日（周二）下午13: 00-15:00
地 点: 闵行校区行政楼12楼偏微分方程中心1202报告厅

2011年11月04日

算子代数与非交换几何学术报告

题 目：一类非交换Orbifold的K理论的计算。
报告人：姚一隽副研究员(复旦大学)
时 间：11月8日（星期二）下午3:00
地 点：闵行数学楼102报告厅
摘 要：
二维非交换环面是非交换几何中最基本最重要的对象之一。如果其上有一个离散群的作用，那么我们可以视之为某种非交换的Orbifold. 近年Siegfried等人曾经用比较高深的工具计算这类代数的K-群。这里我们用一种相对比较初等的方法(M.Rieffel的严格形变理论)来计算这一类K-群。这里会看到分析中的Weyl形变在算子代数理论中的应用。我们将使得报告尽可能地易懂。

2011年11月04日

报告题目：The case of the Missing Cage
报告人： Professor Moshe Rosenfeld
（University of Washington, Tacoma, USA）
时间：2011年11月7号（周一）上午10:00-11:00
地点：华东师大闵行校区数学系102报告厅
Abstrast: Does the strongly regular graph G(3250, 57, 0, 1) (a regular graph of order 3250, regular of degree 57, with girth 5) exist?
A beautiful theorem of Hoffman and Singleton asserts that the only possible graphs G(r^2+1, r, 0, 1) are for r = 2, 3, 7, 57.The unique graphs with these parameters are C_5,
Petersen's graph and the Hoffman-Singleton G(50,7,0,1) graph. The existence of G(3250, 57, 0, 1), the missing cage, is still open.
There is a unified construction that constructs the Petersen and Hoffman-Singleton graphs. It suggest a strategy for constructing the "missing cage."
It has the "correct" ingredients and "arithmetic". In this talk I will go over Hoffman-Singleton's beautiful proof and the constructions using finite projective spaces.

2011年11月02日

组 合 数 学 学 术 报 告
运筹控制论组


题 目：A survey on spherical designs and algebraic combinatorics on spheres
报告人：Eiichi Bannai (上海交通大学)
时 间：2011年11月9日（星期三）上午10:00
地 点：闵行数学楼102报告厅
摘 要：This is a survey talk for general audience based on the paper:
Eiichi Bannai and Etsuko Bannai, A survey on spherical designs and algebraic combinatorics on spheres, Europ. J. Combinatorics 30 (2009), 1392-1425.
In this talk, we will mainly discuss the following topics.
(i) Concept of spherical t-designs,
(ii) Spherical t-designs which are orbits of a finite group,
(ii) Spherical t-designs which are shells of a Euclidean lattice,
(iv) The existence and explicit construction problems of spherical t-designs,
(v) Study of spherical t-designs from the viewpoint of algebraic combinatorics, and
(vi) Universally optimal configurations on the sphere in the sense of Cohn-Kumar.


报告人简介


坂内英一 （Eiichi Bannai）教授1974年获得东京大学博士学位，曾在东京大学、学习院大学、俄亥俄州立大学、九州大学等著名高校任教，是国际代数组合领域的领军人物和研究先驱。坂内教授早期从事群论的研究，后来逐渐转向组合数学领域。他与依藤达郎教授合写的专著(E. Bannai, T. Ito, Algebraic Combinatorics, I, Associatoion Schemes, Benjamin/Cummings, 1984.)是世界上第一本使用代数组合学这一名称的专著，1987年被翻译成俄文出版，已经成为代数组合领域的经典书籍，在谷歌学术搜索可查到有近1100次的引用率。坂内教授已发表110多篇研究论文，研究内容包括组合数学（图，设计，码，结合方案，球面设计等）、有限群、数论（格和模形式）、正交多项式(Askey-Wilson 正交多项式)、数值分析中的积分公式、数学物理（自旋模型与能量极小化构型）等。他是8份国际杂志的编委，曾组织过多次代数与组合方面的国际学术会议，包括与万哲先院士一起在1994年组织了第一届中日代数组合国际会议。荣获1979年俄亥俄州立大学颁发的Distinguished Research Award和2007年日本数学会颁发的2007 Algebra Prize。坂内教授的最大梦想是从代数组合的角度对有限单群分类给出新的理解和推广。

2011年11月02日

运筹与控制组学术报告
报 告 人： Dr Sanming Zhou
(Department of Mathematics and Statistics, The University of Melbourne，Australia)
报告人简介：周三明博士目前是墨尔本大学的Reader. 他在离散数学许多领域（如Algebraic Combinatorics, Combinatorial Optimization, Random Graph Processes and Randomized Algorithms）做出过出色成果，他曾获得2003年 Kirkman 奖。
时 间：2011年11月3日（星期四）下午13：00-14：00
地 点：闵行校区数学楼129教室
报告题目: Distance three labellings of graphs
摘要： Let h be a positive integer. An L(h,1,1)-labelling of a (finite or infinite) graph is an assignment of nonnegative integers (labels) to its vertices such that adjacent vertices receive labels with difference at least h, and vertices distance two or three apart receive distinct labels. The span of such a labeling is the difference between the maximum and minimum labels used. Motivated by applications in frequency assignment, the L(h,1,1)-labelling problem seeks for the minimum span over all L(h,1,1)-labellings of a graph together with an optimal L(h,1,1)-labelling.
In this talk I will review recent progress on the L(h,1,1)-labelling problem.

欢迎广大师生参加!

2011年11月01日

《师魂——华东师范大学老一辈名师》系列报告会
时间：2011年11月2日下午
地点：闵行校区第三教学楼109报告厅
流程：
14:45 数学月开幕式（指导教师林磊老师致辞，协会会长介绍活动安排）
15:00 张奠宙先生的报告，“继承传统 推陈出新 ——回忆建校初期的数学系”。
15:45 王建磐校长的报告 “把代数研究带到国际前沿的曹锡华教授”。

2011年10月28日

数学系-偏微分方程中心联合讨论班
题 目: Stability of traveling waves for the relaxation system via spectral analysis
报告人: 李敬宇博士（华师大偏微分方程中心博士后）
时 间: 2011年11月1日（周二）下午13: 00-15:00
地 点: 闵行校区行政楼12楼偏微分方程中心1202报告厅

2011年10月26日

曹锡华代数论坛
Title:　Number Theory behind Series for $1/\pi$
报告人：孙智伟教授（南京大学）
时间：2011年10月28号 14点至15点
地点：闵行数学楼102室
Abstract： One of the main contributions of Ramanujan is that he recorded 17
mysterious hypergeometric series for $1/\pi$ in 1914 which are
related to elliptic integrals and modular forms and were not all
proved until 1987. In this talk we will introduce the speaker's
nearly 160 conjectural series for powers of $\pi$ (most of which are
about series for $1/\pi$) discovered recently and explain how they
were found. The number theory behind those series includes $p$-adic
congruences involving Bernoulli or Euler numbers, and the
determination of $x^2$ mod $p^2$ for primes $p$ with $4p=x^2+dy^2$,
where $d$ is a positive integer with the imaginary quadratic fields
$\Bbb Q(\sqrt{-d})$ having class number among 1, 2, 4, 8.

报告人简介：孙智伟，1965年10月生。2005年获得国家杰出青年科学基金。现为南京大学数学系教授、博士生导师，数学与应用数学专业主任，其研究方向为数论与组合。

2011年10月25日

组 合 数 学 学 术 报 告
运筹控制论组

报告人：Prof. Stephan Wagner(Stellenbosch University)

题 目：Parameters of integer partitions - a zoo of limit laws

时 间：11月1日（星期二）下午15:00-16:00）

地 点：数学楼102报告厅

摘 要：Limit laws for various parameters of integer permutations and their generalizations (where the parts are restricted to certain sets, e.g. the set of all squares or all primes) are presented. Various classical distributions (Gaussian, Rayleigh, Gumbel, Geometric) as well as more "exotic" distributions occur as limit laws in this context. For certain parameters, interesting phase transitions can be observed as well.

2011年10月24日

数学系-偏微分方程中心联合讨论班

题目：Some topics on the stability of basic waves for the viscous conservation laws

报告人：李敬宇 博士（华师大PDE中心博士后）

时 间：2011年10月25日（周二）下午13: 00-15:00
地 点： 闵行校区行政楼12楼偏微分方程中心1202报告厅

2011年10月21日

Title: Integrable representations of affine superalgebras （仿射李超代数的可积表示）
报告人：吴月柱 博士后 （常熟理工学院副教授）
时间： 10月28日 10:00-11:00
地点：闵行数学楼102报告厅

Abstract: All irreducible integrable representations with finite-dimensional weight spaces over affine Lie algebras were classified by Chari. But there only exist trivial integrable representations for almost all affine superalgebras if the level is nonzero. In this talk I will show that all irreducible integrable level zero modules with finite-dimensional weight spaces over affine superalgebras are loop modules. This is a joint work with Prof. R.B. Zhang.

2011年10月10日

报告时间：2011年10月31日上午10:00---11:00

报告地点：数学系闵行校区报告厅102室

主讲人：美国科学院院士、MIT数学系国际代数群与量子群表示论领袖级专家G. Lusztig 教授

报告题目：从Weyl群中的共轭类到幂幺类（From conjugacy classes in the Weyl group to unipotent classes）
We define a surjective map from the set of conjugacy classes in the Weyl group of a reductive connected group G to the set of unipotent classes of G.
This explains why the second set has at most as many elements as the first set.

2011年10月10日

短期课程(五)

报告人：左康 教授 德国 Mainz 大学

题目：椭圆曲线和阿贝尔簇的几何与算术

时间： 10月12日（周三）下午1:00-4:00

地点： 4教楼406教室

2011年10月09日

主 题：On a free boundary problem
报告人：郭宗明教授（河南师范大学）
时 间：2011年10月11日（周二）下午13: 00-14: 30
地 点：闵行校区行政楼12楼偏微分方程中心1202报告厅
报告人简介：
郭宗明教授，理学博士。1982年6月在新乡师院数学系毕业， 获学士学位；1987年6月在中科院数学所毕业，获硕士学位；1992年12月获英国Glasgow大学数学博士学位； 1992年9月至1994年3月在澳大利亚New England大学和Sydney大学进行博士后研究。2006年至今为河南师范大学特聘教授。曾任中国数学会理事，河南省数学会理事长，主持过国家教育部科技项目，河南省杰出青年基金项目等。郭宗明教授主要从事椭圆型方程和方程组的研究,取得了一系列有国际影响的研究成果。

2011年10月09日

题目: Spherical derivative and more
报告人: Dr. Shahar Nevo (Bar-Ilan University, Israel)
时间：2011年10月9日 下午13：00-15:00
地点：闵行校区数学楼102报告厅

摘要: We prove that if $\mathcal{F}$ is a family of meromorphic function in a domain $D$ and $\{\rho^\sharp:\rho\in\mathcal{F}\}$ is locally bounded away from zero, then $\mathcal{F}$ is normal. We derive from this result the existence of some universal constant and calculate it. This work is jointly with S. Grahl. Separately we obtain a new formula for the natural logarithm of natural number that generalize the know formula for $\ln 2$.

2011年10月08日

题 目：一些有限维代数的表示理论
报告人：芮和兵 教授
时 间：10月17日下午 13:00－14:00
地 点：闵行校区数学楼102报告厅
报告人简介：
芮和兵，1994年毕业于华东师范大学数学系, 获博士学位。现为华东师范大学数学系教授，博士生导师。研究领域: Lie理论中的有限维代数的表示理论。
报告内容简介：
我将介绍一些与典型李代数、量子群有关的有限维代数，并解释这些有限维代数的表示理论与李代数、量子群的表示理论之间的联系。

2011年10月08日

题 目：p-adic Hodge theory in algebraic geometry
报告人：左康 教授 （德国 Mainz 大学，华东师范大学千人计划）
主持人：谈胜利 教授
时 间：10月11日下午14:00 - 15:00
地 点：闵行校区数学楼102报告厅
报告人简介：
左康，德国 Mainz 大学教授，华东师范大学千人计划入选者。1978-1981在中国科学技术大学数学系读书。1981-1984德国波恩大学数学系读硕士。1984-1988德国波恩大学读博士，获德国波恩大学博士；1988-1990波恩Max-Planck数学研究所博士后。1990-1997任Kaiserslautern大学讲师；1997-2000 Kaiserslautern大学 (Heisenberg Fellowship). 2000-2004香港中文大学数学所访问教授. 2004.7起任德国Mainz大学首席教授。左康教授于1997年获得德国Heisenberg奖；2004：华人国际数学家大会1小时特邀报告。
报告内容简介：
I shall briefly explain $p-$adic Hodge structure and variation of $p-$adic Hodge structure arising from Algebraic Geometry. I will also discuss the correspondence between Higgs bundles and de Rham bundles in characteristic $p$ via variation of $p-$adic Hodge structure.

2011年10月08日

题 目：绳圈上的数学
报告人：邱瑞锋 教授 （华东师范大学，国家杰出青年基金获得者）
主持人：周风 教授
时 间：10月13日下午 13:00－14:00
地 点：闵行校区数学楼102报告厅
报告人简介：
邱瑞锋，华东师范大学数学系教授。1964年出生，1983年考入吉林大学数学系学习，1993年在吉林大学数学研究所获博士学位。主要研究方向是几何拓扑学，主要成就包括证明Gordon猜想，与他人合作发现Heegaard分解沿闭不可压缩曲面的融合积可同时稳定化多次的现象，以及给出可约Dehn手术与平环Dehn手术的最小几何数和可约Dehn手术与环面Dehn手术的最小几何数的最佳估计。2007年获得国家杰出青年基金项目。
报告内容简介：
绳圈，数学上称之为纽结。纽结理论是当前拓扑学研究的热点之一，并已在力学及生命科学等方面有诸多应用。报告将介绍上世纪80年代取得的关于纽结方面的一个简单而深刻结论,并介绍其应用。

2011年09月29日

题 目：数学 － 简单与高深
报告人：席南华 教授（中国科学院院士，中国科学院数学与系统科学研究院）
主持人：周 风 教授
时 间：9月29日下午 15:00—16:00
地 点：闵行校区第三教学楼109报告厅

报告人简介：
席南华院士，数学家。中国科学院数学与系统科学研究院研究员。1963年生于广东省英德，籍贯湖南祁东。1981年毕业于湖南怀化师范专科学校（现怀化学院）数学科，1985年、1988年先后获华东师范大学数学系硕士、博士学位。主要从事代数群与量子群领域研究。对仿射A型Weyl群证明了Lusztig关于双边胞腔的基环的猜想；确定了Deligne-Langlands关于仿射Hecke代数的猜想成立的充要条件。证明了特征p上的非单位根处的量子群的有限维表示的性质与特征0的代数群的表示类似；清楚具体地实现单位根处的量子群的有限维不可约表示；与Chari合作构造了量子群的单项基，计算了某些典范基，给出了根向量之间的一个交换公式。与Lusztig合作发现了典范左胞腔，与Tanisaki合作证明了仿射A型Hecke代数的一个代数滤过和一个几何滤过相同。曾获国家自然科学奖二等奖、陈省身数学奖等。2009年当选为中国科学院院士。
报告内容简介：
我们常常喜欢了解数学的前沿，那里给人的印象都是高深的数学。其实，前沿和高深的数学都是围绕基本问题展开的。很多基本的问题都来自简单的数学。在这个报告中我想用一些例子说明简单的数学其实与高深的数学有着密切的关系，简单的数学能帮助我们认识一些高深和前沿数学的根基是什么。

2011年09月25日

短期课程(四)

报告人：左康 教授 德国 Mainz 大学

题目：椭圆曲线和阿贝尔簇的几何与算术

时间： 9月26日（周一）下午1:00-4:00

地点： 4教楼429教室

（注： 本课程约有五次，每周一次。后面几次课程的具体时间地点待定）

2011年09月22日

题目：差分及微分方程的非局域对称
报告人： 楼森岳 教授
上海交通大学、宁波大学
报告时间：2011年9月28日下午13：30-14：30
报告地址：数学系（闵行）102报告厅

Abstract:
Darboux变换和Backlund变换是可积非线性差分和微分方程研究中的重要方法。利用这两种方法可以把一个方程的解变换成一个新解。因此实质上 Darboux变换和Backlund变换是变化群。然而尽管这两种变换发展一百20多年了，他们对应的对称代数问题基本无人问津。本报告主要讨论我们最 近在这方面的研究进展。指出不同变换对应的对称是非局域对称和一般对称并提出非局域对称的局域化方法。利用非局域对称，人们可以得到有限维和无限维的新的 可积系统，可以得到新的严格解。也可能给出一条研究全差分方程Schwarz形式的新途径。

2011年09月22日

学术报告
主 题： Further Study Of Supercritical Elliptic Equations (I)
报告人：郭宗明教授（河南师范大学）
时 间：2011年9月27日（周二）下午13: 00-14: 30
地 点：闵行校区行政楼12楼偏微分方程中心1202报告厅
报告人简介：
郭宗明教授，理学博士。1982年6月在新乡师院数学系毕业， 获学士学位；1987年6月在中科院数学所毕业，获硕士学位；1992年12月获英国Glasgow大学数学博士学位； 1992年9月至1994年3月在澳大利亚New England大学和Sydney大学进行博士后研究。2006年至今为河南师范大学特聘教授。曾任中国数学会理事，河南省数学会理事长，主持过国家教育部科技项目，河南省杰出青年基金项目等。郭宗明教授主要从事椭圆型方程和方程组的研究,取得了一系列有国际影响的研究成果。

2011年09月19日

报告人：Rolf Farnsteiner教授 （德国Kiel大学）
演讲题目： NILPOTENT OPERATORS, CATEGORIES OF MODULES, AND
AUSLANDER-REITEN THEORY （I）
时间：2011年10月8日（周六）上午，10：00-11：00
地点：闵行校区数学楼102报告厅
演讲摘要：
The theory of rank varieties, expounded in the early 1980s by Jon Carlson for modular repre-
sentations of finite groups, was designed as a tool to understand cohomological support varieties. Subsequent work by Jantzen, Friedlander-Parshall and Suslin-Friedlander-Bendel showed that similar methods can be introduced for representations of restricted Lie algebras and infinitesimal group schemes. About five years ago, Friedlander and Pevtsova have unified and extended the afore-mentioned approaches by introducing representation-theoretic supports for finite group schemes. The elements of these topological spaces are equivalence classes of at algebra homomorphisms α: kZ/(p) → kG between the group algebras of the cyclic group with p-elements (p = char(k)) and a finite group scheme G. These maps give rise to p-nilpotent operators on G-modules that have been used to define new invariants on the one hand, while leading to new full subcategories of mod G on the other.
Starting with a review of the historical origins, we first look at rank varieties in the abovementioned contexts, briey touching upon their cohomological aspects. The second lecture introduces the notion of a p-point and gives the connection between rank varieties and the space of equivalence classes of p-points. In preparation for our applications, we also discuss the extent to which G-modules are determined by the action of their p-nilpotent operators. The last two lectures are concerned with new invariants arising via p-points. Being finer than those associated with rank varieties, they actually provide new insight even within the classical" contexts of finite groups and restricted Lie algebras. Operators of p-points have been employed to identify three full subcategories of mod G, consisting of modules of constant Jordan type (Carlson-Friedlander-Pevstova, 2008), modules of constant
rank (Friedlander-Pevtsova, 2010), and modules satisfying the equal images property (Carlson-Friedlander-Suslin, 2011). We explain how the structure and the relationship between these categories depends on the underlying group scheme.
The series ends with applications concerning Auslander-Reiten theory. It turns out that p-points give rise to new invariants for the connected components of the stable Auslander-Reiten quiver Γs(G) of mod G. These are exploited in the study of the interplay between Γs(G) and the abovementioned subcategories.

2011年09月19日

报告人：Rolf Farnsteiner教授 （德国Kiel大学）
演讲题目：NILPOTENT OPERATORS, CATEGORIES OF MODULES, AND
AUSLANDER-REITEN THEORY（III）（IV）
时间：2011年10月12日（周三）上午，10：00-12：00
地点：闵行校区数学楼102报告厅

2011年09月19日

报告人：Rolf Farnsteiner教授 （德国Kiel大学）
演讲题目：NILPOTENT OPERATORS, CATEGORIES OF MODULES, AND
AUSLANDER-REITEN THEORY（II）
时间：2011年10月10日（周一）上午，10：00-11：00
地点：闵行校区数学楼102报告厅
演讲摘要：
The theory of rank varieties, expounded in the early 1980s by Jon Carlson for modular repre-
sentations of finite groups, was designed as a tool to understand cohomological support varieties. Subsequent work by Jantzen, Friedlander-Parshall and Suslin-Friedlander-Bendel showed that similar methods can be introduced for representations of restricted Lie algebras and infinitesimal group schemes. About five years ago, Friedlander and Pevtsova have unified and extended the afore-mentioned approaches by introducing representation-theoretic supports for finite group schemes. The elements of these topological spaces are equivalence classes of at algebra homomorphisms α: kZ/(p) → kG between the group algebras of the cyclic group with p-elements (p = char(k)) and a finite group scheme G. These maps give rise to p-nilpotent operators on G-modules that have been used to define new invariants on the one hand, while leading to new full subcategories of mod G on the other.
Starting with a review of the historical origins, we first look at rank varieties in the abovementioned contexts, briey touching upon their cohomological aspects. The second lecture introduces the notion of a p-point and gives the connection between rank varieties and the space of equivalence classes of p-points. In preparation for our applications, we also discuss the extent to which G-modules are determined by the action of their p-nilpotent operators. The last two lectures are concerned with new invariants arising via p-points. Being finer than those associated with rank varieties, they actually provide new insight even within the classical" contexts of finite groups and restricted Lie algebras. Operators of p-points have been employed to identify three full subcategories of mod G, consisting of modules of constant Jordan type (Carlson-Friedlander-Pevstova, 2008), modules of constant
rank (Friedlander-Pevtsova, 2010), and modules satisfying the equal images property (Carlson-Friedlander-Suslin, 2011). We explain how the structure and the relationship between these categories depends on the underlying group scheme.
The series ends with applications concerning Auslander-Reiten theory. It turns out that p-points give rise to new invariants for the connected components of the stable Auslander-Reiten quiver Γs(G) of mod G. These are exploited in the study of the interplay between Γs(G) and the abovementioned subcategories.

2011年09月19日

短期课程(二)
报告人：左康 教授(德国 Mainz 大学)

题目：椭圆曲线和阿贝尔簇的几何与算术

时间： 9月16日（周五）下午1:00-4:00

地点： 4教楼229教室

（注： 本课程约有五次，每周一次。 后面几次课程的具体时间地点待定）

2011年09月19日

短期课程(三)

报告人：左康 教授 德国 Mainz 大学

题目：椭圆曲线和阿贝尔簇的几何与算术

时间： 2011年9月23日（周五）下午1:00-4:00

地点： 4教楼429教室

2011年09月19日

题目：The Calabi-Yau Equations on Closed Symplectic Manifolds
报告人： 王宏玉 教授
扬州大学
报告时间：2011年9月28日下午14：10-15：10
报告地址：数学系（闵行）129

2011年09月19日

华东师范大学60周年校庆学术报告

题 目：从平行公理谈起
报告人：王诗宬 教授（中国科学院院士，北京大学）
时 间：9月21日（周三）下午13:30 - 14:30
地 点：闵行校区数学楼102报告厅

报告人简介：
王诗宬院士，数学家，北京大学教授。1953年生于江苏省盐城市。1988年在美国加州大学洛杉机分校获博士学位。长江特聘教授。曾获中国青年科学家奖、求是杰出青年奖、国家杰出青年基金、陈省身数学奖、 国家自然科学奖二等奖。从事低维拓扑研究。与合作者一起发现了三维流形中不能提升为有限复叠空间嵌入曲面的第一个本质浸入曲面的例子，在三维流形中心问题本质Haken猜测的研究引人注目，为几何群论专家所称道。与他人合作，对可几何化流形证明了Thurstou关于复叠度的猜测证明了几个有限性定理，并给出不可约几何三维流形自同胚的标准型，对三维流形间非零度映射的研究作了重要的推动。在纽结手术方面也有佳作。发现了卫星结上实行循环手术的障碍与他人合作得到纽结补中本质浸入曲面边界数的有限性定理。2005年当选为中国科学院院士。

2011年09月19日

华东师范大学60周年校庆学术报告

题 目：Generalized Witten genus and vanishing theorem
报告人：张伟平 教授（中国科学院院士，南开大学）
时 间：9月22日（周四）上午10:00 - 11:00
地 点：闵行校区数学楼102报告厅

报告人简介：
张伟平院士，数学家，陈省身数学研究所教授，博士生导师，教育部“长江学者奖励计划”特聘教授，中国科学院院士，第三世界科学院院士。生于1964年，1985年本科毕业于复旦大学数学系，1988年硕士毕业于中国科学院数学研究所，同年考入南开数学研究所，1990年自南开公派赴法国留学，1993年博士毕业于巴黎南大学，同年回南开大学任教。2001年当选第三世界科学院院士。曾获第三世界科学院数学奖、国家自然科学二等奖、长江学者成就奖一等奖、中国数学会陈省身数学奖、香港求是基金会杰出青年学者奖，被授予“中国十大杰出青年”、“全国先进工作者”等称号，曾在国际数学家大会上做45分钟特邀报告。2007年当选中国科学院院士。

报告内容简介：
We report a joint work with Qingtao Chen and Fei Han. We construct a generalized Witten genus for spinc manifolds, which takes values in level 1 modular forms with integral Fourier expansion on a class of spinc manifolds called stringc manifolds. We also construct a mod 2 analogue of the Witten genus for 8k+2 dimensional spin manifolds. The Landweber-Stong type vanishing theorems are proven for the generalized Witten genus and the mod 2 Witten genus on stringc and string (generalized) complete intersections in (product of) complex projective spaces respectively.

2011年09月09日

短期课程系列(一)

报告人：左康 教授 德国 Mainz 大学

题目：椭圆曲线和阿贝尔簇的几何与算术

时间： 2011年9月9日（周五）下午1:00-4:00

地点： 4教楼229教室

2011年09月02日

报告题目：A new index theory and multiple non semi-trivial solutions for elliptic systems
报告人：张恭庆 教授 （中国科学院院士、北京大学）
时间：2011年9月6日 上午10：00-11：00
地点：闵行数学楼102报告厅

2011年09月02日

曹锡华代数论坛
演讲题目(Title) : On the Gelfand-Kirillov conjecture
演讲人(Speaker): Dr. Jean-Marie Bois
(Christian-Albrechts-Universität zu Kiel)
时间(Time)：2011年9月8日（周四）,10: 00am-11:00am
地点(Venue)：闵行校区数学楼102报告厅
摘要(Abstrct)： The classical Gelfand-Kirillov conjecture concerns the structure of enveloping skewfields of finite-dimensional Lie algebras over fields of characteristic 0. It can be viewed as a double question of rationality, both in the ordinary commutative sense (for the centre) and in a suitable non-commutative sense (above the centre). In this talk, we will give an overview of the problem, from its origin in 1966 till the most recent developments in the past few years. If time permits, we will mention analogues of the conjecture in different settings (quantum algebra or Poisson geometry).

2011年08月29日

偏微分方程和计算数学学术报告
报告人： 张 镭博士
时 间： 2011年8月31日（星期三）上午：10:00-11:00
地 点： 中山北路校区理科大楼A座1510室
报告题目： Homogenization with non-separable scales
报告摘要：
We consider homogenization of divergence form operators with $L^\infty$
coefficients which allows non-separable scales, in the sense that the solution space is approximated with a finite dimensional space.
Our method does not rely on concepts of ergodicity or scale-separation, but on the property that the solution space of these operators is
compactly embedded in $H1$ if source terms are in the unit ball of $L2$
instead of the unit ball of $H^{-1}$. Approximation spaces are generated
by solving elliptic PDEs on localized sub-domains with source terms
corresponding to approximation bases for $H2$. The $H1$-error estimates
show that $\mathcal{O}(h^{-d})$-dimensional spaces with basis elements
localized to sub-domains of diameter $\mathcal{O(h^\alpha
\ln\frac{1}{h})$ (with $\alpha \in [1/2,1)$) result in an
$\mathcal{O}(h^{2-2\alpha})$ accuracy for elliptic, parabolic and
hyperbolic problems. The proposed method can be naturally generalized to
vectorial equations (such as elasto-dynamics).

报告人简介：
主要教育学历
Ph.D., 2007, California Institute of Technology, Pasadena
Advisor: Professor Houman Owhadi

Thesis: Metric based upscaling for partial differential equations

M.S., 2002, Chinese Academy of Sciences, Beijing

Advisor: Professor Li Yuan

Thesis: Level set method for two component compressible ow simulation.

B.S., 1999, Peking University, Beijing, China.

主要研究经历

Jun.2010 - Jun,2012, Research Associate, Mathematical Institute, Oxford University

Apr.2009 - May.2010, Postdoc scholar, Hausdor Center for Mathematics, Bonn, Germany

Sep.2007 - Mar.2009, Postdoc scholar, Max Planck Institute for mathematics in sciences, Leipzig, Germany.

研究方向
Research: Multiscale analysis and modeling in science and engineering

Interest: Numerical analysis and scientific computing, Homogenization of partial differential equations,

Quasi-continuum method and its application in material science

2011年08月08日

题目：Some Recent Results in Preconditioning Techniques and Tensors
报告人：Professor Michael Kwok-Po Ng (香港浸会大学数学系)
时间：2011年8月14日（周日） 14:30－15:30
地点：中山北路校区 理科大楼A1510

摘要：
In this talk, I would like to share my recent results in
(i) preconditioning techniques like dimensional factorization preconditioners, and
(ii) eigenvalues and eigenvectors of tensors.

2011年07月13日

学术报告

报告人：Manuel Gonzalez Villa博士（德国海德堡大学）

时间：2011年8月3日(周三)下午2:00-3:00

地点：闵行校区数学楼102报告厅

The geometry of quasi-ordinary hypersurface singularities

A germ of equidimensional complex analytic variety is said quasi-ordinary if there is a finite projection to an affine space which is unramified outside a normal crossing divisor. Quasi-ordinary hypersurface singularities generalize plane curve singularities and are related to toric singularities.

They were introduced by Jung in the context of the resolution problem for surface singularities.

In the talk we discuss the geometry of these singularities including some results obtained in collaboration with P.D. Gonzalez-Perez and N. Budur.

2011年07月13日

曹锡华数学论坛
演讲题目： A BGG-type resolutions for irreducible modules over Lie superalgebras
演讲人: 林牛教授 (台湾成功大学)
时间：2011年7月19日（周二）上午，10：00-11：30pm
地点：闵行校区数学楼126报告厅
摘要：We construct a Bernstein-Gelfand-Gelfand type resolution in terms of direct sums of Kac modules for the finite-dimensional irreducible tensor representations of the general linear superalgebra. We also discuss BGG type resolutions in terms of direct sums of certain parabolic Verma modules for certain irreducible modules of classical superalgebras.

2011年07月04日

计算数学学术报告
报告人：
Dr. Pengtao Sun
Dept. of Mathematical Sciences
University of Nevada Las Vegas

报告题目：
Dirichlet/Robin Iteration-by-subdomain DDM For Multiphase PEMFC With Micro-porous Layer

时间： 2011年7月4日（星期一）下午：13:30-14:30

地点： 闵行校区数学楼126报告厅

报告摘要：
In this talk, an efficient numerical method for a three-dimensional, two-phase transport model is presented for polymer electrolyte fuel cell (PEFC) including multi-layer diffusion media, composed of two or more layers of porous materials having different pore sizes and/or wetting characteristics. Particularly, capillary pressure is continuous, whereas liquid saturation is discontinuous, across the interface of gas diffusion layer (GDL) and micro-porous layer (MPL), which can improve liquid-water transport in the porous electrode. We design a nonlinear Dirichlet/Robin iteration-by-subdomain domain decomposition method to deal with water transport in such multi-layer diffusion media, where Kirchhoff transformation and its inverse techniques are employed to conquer the discontinuous water diffusivity in the coexisting single- and two-phase regions. In addition, the conservation equations of mass, momentum, charge, hydrogen and oxygen transport are numerically solved by finite element-upwind finite volume method. Numerical simulations demonstrate that the presented techniques are effective to obtain a fast and convergent nonlinear iteration for a 3D full PEFC model within around a hundred steps. A series of numerical convergence tests are carried out to verify the efficiency and accuracy of our numerical algorithms and techniques.

2011年06月27日

题目: Harnack Inequalities, Heat Kernel Estimates and the Ricci flow

报告人： Professor Xiaodong Cao(Cornell University)
时间： 2011年7月5日下午14：00

地点： 数学系（闵行）126

Abstract：
In this talk, we will discuss about Li-Yau-Hamilton type differential
Harnack inequalities, heat kernel estimates and their applications to
study type I ancient solutions of the Ricci flow. Some of this is joint
work with Q. S. Zhang.

2011年06月22日

数学系--偏微分方程中心联合讨论班
Department of Mathematics- Center for PDE
Joint Seminar

报告题目: Finite element methods for Ginzburg-Landau equations of superconductivity
演讲人： Professor Lin Ping
University of Dundee, UK
时间： 2011年6月23日（星期四）下午1：00-2：00
地点： 华东师大闵行校区数学楼102报告厅


摘要： We use continuous finite element method to show the boundary layer behavior of the order parameter of the minimizing solutions of the Ginzburg-Landau equations. This result confirms the mathematical analysis on boundary effect to the concentration behavior of surface superconductivity as well as the distribution of the vortices.

2011年06月22日

数学系--偏微分方程中心联合讨论班
Department of Mathematics- Center for PDE
Joint Seminar

报告题目: Mean Exit Time of Brownian Particle from Small Windows on the Closed Container

演讲人：Professor Xinfu Chen (University of Pittsburgh)

时间：2011年6月27日（星期一）下午1:00

地点：华东师大闵行校区数学系102报告厅

Abstract

This talk explains the problem of calculating the expectation of exit
time of a Brownian particle confined in a closed container except small
windows on the boundary at which the particle can escape.When the windows are small, asymptotic expansion on the sizes of window is useful in many applications.
In this talk I will present asymptotic formulas as well as an exact solution in a 2-D circular domain with one window of arbitrary size.

2011年06月20日

报告题目: 随机拟微分算子与随机偏微分方程的Calderon型唯一性定理
演讲人： 张旭（四川大学，中科院）
时间： 2011年6月22日（星期三）上午10:00—11:00
地点： 华东师大闵行校区数学系126会议厅

摘要：我们引入了随机拟微分算子的概念，并讨论了相应的象征演算、渐近展开、拟局部性质、有界性理论、椭圆算子与Garding不等式等。作为应用，我们建立了关于一般随机偏微分方程的Calderon型唯一性定理，该结果退化到确定性情形时对熟知的经典结果还略有改进。唯一性定理的证明基于一个新的Carleman型估计。（该工作系与柳絮博士合作完成）

2011年06月20日

组合数学学术报告 [运筹控制论组]

报告人：Paul Barry
Waterford Institute of Technology, Ireland.
题 目：Recent applications of Riordan arrays to combinatorics
时 间：2011年6月24日（星期五上午10:30）
地 点：闵行数学楼102报告厅
摘 要：
We explore some recent results about Riordan arrays and orthogonal
polynomials, and apply these results to the study of some well-known
combinatorial polynomials and to the enumeration of permutations. In
particular we characterise certain combinatorial polynomials as the
moments of families of orthogonal polynomials. We also apply Riordan
arrays to the study of generalised Catalan numbers.

2011年06月20日

报告题目：Rogers-Ramanujan type identities: Extensions, continued
fractions, Engel expansions
报告时间：2011年6月29日星期三 上午10:00-11:00
报告地点：闵行数学楼102
报 告 人： Helmut Prodinger
Department of Mathematics, Stellenbosch University

摘要：

Lucy Slater collected a list of over 100 identities that resemble the
famous Rogers-Ramanujan identities.
Garrett, Ismail and Stanton combined the Rogers-Ramanujan identities
into a one parameter family of identities.
Using finite versions due to (mostly) Drew Sills, this can also be
achieved for many other pairs and triplets from
Slater's list.
The quotient of the Rogers-Ramanujan identities has a nice continued
fraction expansion. Many other ones
from Slater's list as well, and many of them are new.

These results where obtained together with Nancy Gu.

Engel expansions for Rogers-Ramanujan identities where introduced by
John Knopfmacher and later studied
by Andrews et al. We report how Sills' finitizations can be used to
create many other (pseudo) Engel expansions for
other expansions appearing in Slater's list.

2011年06月17日

学 术 报 告
报 告 人： 郁星星教授
(School of Mathematics, Georgia Institute of Technology，我校紫江讲座教授)
时 间：2011年6月14日（星期二）上午10：00
地 点：闵行校区数学楼102教室
报告题目: Subdivisions of $K_5$ in graphs containing $K_{2,3}$

Abstract:
Seymour conjectured that every 5-connected nonplanar graph contains a subdivision of $K_5$. We prove this conjecture for graphs containing $K_{2,3}$. As a consequence, Seymour's conjecture is true if the answer to the following question of Mader is affirmative: Does every simple graph on $n\ge 4$ vertices with at least $12(n-2)/5$ edges contain a $K_4^-$, a $K_{2,3}$, or a subdivision of $K_5$? Joint work with K. Kawarabayashi and J. Ma.
欢迎广大师生参加!

2011年06月17日

曹锡华代数论坛

报告人：陈北方教授（香港科技大学）

时间：2011年6月21日(周二)上午10：30-11:30

地点：闵行校区数学楼102报告厅

Title: Counting patterns and geometric measures

Abstract: In many occasions counting the number of objects of finite
sets parameterized by a family of integers gives rise to a polynomial
function of the family of the integers. For instance in graph
theory, counting the number of proper colorings of a graph by $n$
colors gives rise to the chromatic polynomial function of $n$; the
polynomial comes from the counting patterns $n^k$, the number of
colorings of a $k$ element set by $n$ colors without restriction. If
the number of elements to be counted in sets are infinite, the
ordinary counting does not make sense. However, in some occasions
the counting patters are still there, and give rise to power series
or asymptotic formulas. In this talk, I shall exhibit a number of
examples from the viewpoint of counting or measuring finite and
infinite sets with structures, including an example of interpreting
the generating function of partitions of integers as the total
measure of the Grassmannian of infinite-dimensional subspaces of the
vector space ${\Bbb K}^\infty$ over a field $\Bbb K$.

2011年06月16日

报告题目: Stationary Solutions of Stochastic Retarded Linear Equations with Additive Noise
演讲人： Prof. Kai LIU （The University of Liverpool, UK）
时间： 2011年6月23日（星期四）上午10:00—11:00
地点： 华东师大闵行校区数学系126会议厅

摘要
In this talk, we shall consider stationary (mild) solutions for a class of retarded functional linear differential equations with additive noise in Hilbert spaces. We first introduce a family of retarded Green operators for the stochastic systems. A criterion imposed on the Green operators is presented to identify a unique stationary solution for the systems considered. Under strong quasi-Feller property, it is shown that this criterion is a sufficient and necessary condition to guarantee a unique stationary solution.

2011年06月15日

报告题目: Poiseuille flow and apparent viscosity of nematic liquid-crystals

演讲人：Professor Liu Weishi (University of Kansas)

时间：2011年6月16日（星期四）下午3:20—4:20

地点：华东师大闵行校区数学系102报告厅

摘 要
In this talk, we will study the steady Poiseuille flow of nematic liquid-crystals. A good understanding of this flow can be obtained due to a rather surprising observation that takes advantage of a special structure of this specific problem. As an application of the dynamics of the Poiseuille flow, we provide an approximation for the apparent viscosity -- an important characteristic quantity for fluids.

2011年06月14日

曹锡华代数论坛

报告人：Laurentiu Maxim 教授 （威斯康星大学麦迪逊分校, University of Wisconsin Madison）

时间：2011年6月20日(周一)下午15:00-16:00

地点：闵行校区数学楼102报告厅

Title of talk: "Intersection Space Cohomology and Hypersurface Singularities"

Abstract: "A recent homotopy-theoretic procedure due to Banagl assigns to a certain singular
space a cell complex, its intersection space, whose rational cohomology possesses Poincare
duality. This yields a new cohomology theory for singular spaces, which has a richer
internal algebraic structure than intersection cohomology (e.g., it has cup products), and
which addresses certain questions in type II string theory related to massless D-branes
arising during a Calabi-Yau conifold transition.
While intersection cohomology is stable under small resolutions, in recent joint work with
Markus Banagl we proved that the new theory is often stable under smooth deformations of
hypersurface singularities. When this is the case, we showed that the rational cohomology of
the intersection space can be endowed with a mixed Hodge structure compatible with Deligne's
mixed Hodge structure on the ordinary cohomology of the singular hypersurface."

2011年06月01日

报告人：Richard A. Brualdi教授（美国Wisconsin大学，Madison）
题目：Matrix Classes: Old and New
时间：2011年6月3日（周五） 上午10：00
地点：闵行数学楼126会议室
摘要：Classes of (0,1) and, more generally, nonnegative integral matrices are basic to combinatorics and graph theory and have had a long history. Early investigations were largely concerned with the structure of such classes and the extreme values of various combinatorial parameters. Some new classes (generalizing the Gale-Ryser classes in an unexpected way) and a new parameter (motivated by the study of combinatorial batch codes) have been recently introduced. We shall give an exposition of these old and recent developments.

报告人简介：组合矩阵论的主要奠基人和热情推动者之一，Linear Algebra and its Applications 和Electronic J. of Combinatorics 两本杂志的主编，Discrete Math., Mathematical and Computer Modeling 等5本杂志的编委。

2011年06月01日

时间：2011年6月4日下午一点至四点
地点：中山北路理科大楼A座1414室
题目：On Volume conjecture
报告人：李维萍 （Oklahome State Univ.）

2011年06月01日

时间：2011年6月4日下午一点至四点
地点：中山北路理科大楼A座1414室
题目：Rank and Heegaard genus of 3-manifolds
报告人：李韬 （Boston College）

2011年05月23日

Canard Cycles in Predator-Prey Competition System with Holling type of functional responses

演讲人： Prof. Huaiping Zhu (York University)
时间： 2011年5月23日（星期一）上午9:40 – 11:00
地点： 华东师大闵行校区数学系126报告厅

Abstract.
There have been extensive stability and bifurcation studies of predator-prey type of systems, yet the study of canard cycles of such type of systems is rather limited due to the degenerate singularities and technical difficulties in dealing with the singularities. In this talk, by using the theory of center manifolds and geometric singular perturbation, I will present the bifurcation studies of canard cycles in a general singular perturbed predator-prey systems, and apply the results to obtain canard cycles in the model with different Holling types of functional responses. This is a joint work with Chengzhi Li.

2011年05月20日

报告题目：Traveling Wave Solutions for a Class of Predator-Prey Systems
报告人：Wenzhang Huang（University of Alabama）
时间： 2011年5月20日（星期五）下午15:30—16:30
地点：华东师大闵行校区数学系126会议厅

Abstract: We develop a shooting method to show the existence of traveling wave solutions with an explicit expression of minimum wave speed for a class of predator-prey systems, including systems with traditional Holling types of functional responses. Our approach is a significant improvement of techniques introduced by Dunbar. The advantage of our method is that it does not require the construction of a corresponding, complicated Wazewski's set, which was one of major steps in Dunbar's approach. Our method is more efficient to study the existence of traveling wave solutions for general predator-prey systems.

2011年05月20日

报告题目：Bifurcation and Stability of Internal Layer Solutions for Singular Perturbed Problems
报告人：Xiao-Biao Lin (North Carolina State University)
时间： 2011年5月20日（星期五）下午14:30—15:30
地点：华东师大闵行校区数学系126会议厅
Abstract: Singularly perturbed equations naturally occur in many areas of engineering, physical and biological sciences. Due to different time scales involved in the equations, the system can have internal layer solutions that exhibit fast and slow behaviors. Fundamental problems such as the construction, asymptotic expansion of the layered solutions have been extensively studied. Less well known are the bifurcation and stability of the internal layer solutions.

In this talk we will discuss a simple example in which, as parameter changes, the number of internal layer solutions can increase through a series of saddle-node bifurcations. A geometric method will be presented which can be used to test the points of bifurcations and to determine the stability of internal layer solutions.

2011年05月18日

题 目： On certain problems in vertex-transitive graphs and finite groups
报告人：张 翠 博士
(University of Primorska, Slovenia)
北京交通大学数学系
时 间：2011年5月11号下午13:00-14:00
地 点：华东师大闵行校区数学系102报告厅

2011年05月18日

题目: The higher order terms in asymptotic expansion of color Jones polynomials

报告人： 朱盛茂 博士（浙江大学）

时间： 5月24日下午2：00-3：00

地点： 中山北路校区（中山北路3663号）， 理科大楼A1414


Abstract:
Color Jones polynomial is one of the most important quantum
invariants in knot theory. Finding the geometric information from
the color Jones polynomial is an interesting topic. In this talk,
we will study the general expansion of color Jones polynomial.
Following the recent works on $SL(2,\mathbb{C})$ Chern-Simons
theory, we present an algorithm to calculate the higher order terms
in general asymptotic expansion of color Jones polynomial from the
view of A-polynomial and noncommutative A-polynomial. We also
give some examples to illustrate how to calculate the higher order terms
by this algorithm.

2011年05月16日

非线性常微分方程解集的分歧

报告人：马如云教授 （西北师范大学）

时间： 2011年5月16日（星期一）下午15:00—16:00

地点： 华东师大闵行校区数学系126会议厅

摘要：非线性微分方程有着极为丰富的源泉，研究它的最基本的方法是线性方程的非线性扰动。
本报告简要介绍线性二阶常微分方程边值问题的特征值理论、非共振问题、共振问题的基本结果；并介绍Rabinowitz 分歧定理及其应用.

2011年05月16日

报告题目：关于脉冲微分系统的研究

报告人：傅希林 教授 （山东师范大学）

时间：2011年5月16日（星期一）下午14:00—15:00

地点： 华东师大闵行校区数学系126会议厅

摘要：脉冲现象作为一种瞬时突变现象，在现代科技的实际问题中是普遍存在的，
其数学模型往往可归结为脉冲微分系统。本报告简要阐述关于脉冲微分系统研究的基本性质，
应用模型及一些最新研究动态。

2011年05月12日

报告人：Prof. Cliff Konold
报告人简介：美国马萨诸塞大学科学说理研究院（Scientific Reasoning Research Institute）院长、科研副教授。在过去的25年中，他致力于研究从幼儿到成人是如何用数据进行说理的，并努力将概率统计教育引入中小学的数学课程。他的这方面工作获得美国NSF合计约1千万美金的资助。他在数学和科学教育、统计、认知心理学、决策研究等领域发表了不少充满智慧的论文。最近几年，他与Key Curriculum 出版社合作，开发了目前已被许多国家用于初中概率统计教育的软件TinkerPlots和其他一些课程资源。

时间：2011年5月16日 (周一) 上午9:45－11:15
地点：数学系102报告厅
题目：Developing Statistical Perceptions

摘要：Statistics is typically portrayed as a set of methods for collecting and analyzing data. But more fundamentally, statistics is a way of seeing the world. I describe our efforts to understand the perceptions and ideas young students bring to bear on data and how we work to shape students' perceptions to make them more like the expert's. To facilitate learning, we have built into the data-visualization software, TinkerPlots, tools that support and then build on novice perceptions. More recently, we have added modeling capabilities which students use to create and explore "worlds" of their own making. In this way, we hope to develop the crucial understanding that statistics is not only about seeing, but also about questioning what we see.

2011年05月12日

报告人：Prof. Cliff Konold
报告人简介：美国马萨诸塞大学科学说理研究院(Scientific Reasoning Research Institute)院长、科研副教授。在过去的25年中，他致力于研究从幼儿到成人是如何用数据进行说理的，并努力将概率统计教育引入中小学的数学课程。他的这方面工作获得美国NSF合计约1千万美金的资助。他在数学和科学教育、统计、认知心理学、决策研究等领域发表了不少充满智慧的论文。最近几年，他与Key Curriculum 出版社合作，开发了目前已被许多国家用于初中概率统计教育的软件TinkerPlots和其他一些课程资源。

时间：2011年5月18日 (周三) 上午9:45－11:15
地点：数学系102报告厅
题目：Reconnecting Data and Chance

摘要：For the past 15 years, pre-university students in many countries including the US have encountered data analysis and probability as separate, mostly independent strands. Research suggests, however, that some of the difficulties students have in learning basic data-analysis skills stem from poor understandings of probability. I describe our recent efforts to develop and test classroom materials to support middle-school students in coming to see the "data in chance" and the "chance in data". Central to our approach is a new modeling and simulation capability that we built into TinkerPlots 2.0. Our activities employ an iterative model-fit process in which students evaluate successive theories by collecting and analyzing data. As distribution features become a focal point of students' explorations, signal-and-noise components of data become visible as variation around an "expected" distribution in repeated samples. An important part of students' learning experiences, and one enhanced through visual aspects of TinkerPlots, is becoming able to see things in data they were previously unable to see.

2011年05月12日

时滞微分方程的周期性和稳定性
演讲人：范猛 教授 （东北师范大学）
时间：2011年5月17日（星期二）下午14:45—15:30
地点：华东师大闵行校区数学系126会议厅

摘要
微分方程的周期性和稳定性是微分方程理论研究中的重要问题之一。本报告研究一类时滞微分方程的周期解的存在性和稳定性。首先，应用Krasnselskiii不动点定理建立了此类方程存在周期解的充分判据，同时讨论了周期解存在的多解性和不存在性。然后，应用Banach压缩映射原理和Schauder不动点定理研究此类方程的稳定性，建立充分性判据。这里所使用的方法不同于经典的Lyapunov第二方法，而是基于不动点定理，此方法可以避免Lyapunov第二方法的一些局限性。

2011年05月12日

Spatial Dynamics of a Nonlocal and Delayed Population Model in a Periodic Habitat
演讲人：翁佩萱教授（华南师范大学）
时间：2011年5月17日（星期二）下午14:00—14:45
地点：华东师大闵行校区数学系126会议厅

摘要
We derived an age-structured population model with nonlocal effects and time delay in a periodic habitat. The spatial dynamics of the model including the comparison principle, the global attractivity of spatially periodic equilibrium, spreading speeds, and spatially periodic traveling wave fronts is investigated. It turns out that the spreading speed coincides with the minimal wave speed for spatially periodic travel waves.

2011年05月09日

曹锡华代数论坛

题目：黎曼曲面之叶化结构

Title: Foliations by Riemann surfaces

报告人：John Erik Fornaess教授 （密歇根大学）

时间：2011年5月9日(周一)下午16:00-17:00

地点：闵行校区数学楼102报告厅

Abstract:

I will talk about compact sets that are foliated by Riemann surfaces. The problem is to develop function theory on such sets. This can be considered as function theory on Riemann surfaces with parameters. I will discuss some recent joint results with Nessim Sibony and Erlend Wold.

2011年05月09日

曹锡华代数论坛

题目：3维紧强拟凸CR流形之间的CR态射的刚性与奇点解消

Title: Resolution of singularities and rigidity of CR morphisms between 3-dimensional compact strongly pseudoconvex CR manifolds.

报告人：丘成栋教授 （伊利诺伊大学）

时间：2011年5月9日(周一)下午15:00-16:00

地点：闵行校区数学楼102报告厅

Abstract:

We shall discuss rigidity phenomenon of CR morphisms between compact strongly pseudoconvex CR manifolds. In particular, we shall prove the following result. Let X_1, X_2 be two 3-dimensional compact strongly pseudoconvex CR manifolds sitting inside a 2-dimensional variety V with only isolated singularities in C^n. Let V_1, V_2 be two varieties in V such that their boundaries are X_1, X_2 respectively. Suppose that V, V_1, V_2 have the same singular set. Then nontrivial CR morphism from X_1 to X_2 are CR biholomorphisms.

As a corollary, we have proven the following Theorem. Let X be a 3-dimensional compact strongly pseudoconvex CR manifolds sitting inside C^n. Then nontrivial CR morphisms from X to itself are automorphisms.

2011年05月09日

时间：2011年5月11日（本周三）
上午：10:10-11:30
地点：数学楼102报告厅
报告人：冯声涯 博士 北京大学数学院
报告题目：Schroedinger 算子的热核分析（变分方法）

2011年05月09日

曹锡华代数论坛
报告人： 意大利 Salento 大学初文昌教授
报告题目: DOUGALL’S BILATERAL SERIES AND RAMANUJAN-LIKE pi-FORMULAE
摘要：The partitial sums of of Dougall‘s bilateral 2H2 and 5H5 series are investigated via iteration
procedure. Several unusual transformation formulae into fast convergent series are established. They
lead surprisingly to numerous infinite series identities involving pi, zeta(3) and Catalan constant,
including several important ones discovered by Ramanujan (1914) and recently by Guillera.
时间： 2011 年 5 月9 号星期一上午9 点半到10 点半.
地点： 数学系 129 报告厅

2011年05月06日

题 目: The exterior square of a Lie algebra
报告人： Peter Schneider (Munster大学教授)
时 间: 2011年3月25日（星期五） 下午 2:30-3:30
地 点: 闵行校区数学楼102报告厅

摘 要：
The Lie bracket of a Lie algebra $L$ induces a linear map $L \wedge L \rightarrow L$.When can the kernel of this map be generated by vectors of the form $x \wedge y$ with $[x,y] = 0$? This seemingly elementary question does not seem to be tractable by elementary methods. I will explain why a number theorist is interested in this question over fields of positive characteristics. I will also sketch joint work with O. Venjakob in which we solve this problem for Chevalley forms of semisimple Lie algebras.

2011年05月06日

数学系--偏微分方程中心联合讨论班
Department of Mathematics- Center for PDE
Joint Seminar

报告题目：On Some Geometric Properties of Solutions to Magnetic Schrodinger Equations
演讲人：刘单博士
华东师范大学
时间：2011年3月24日（星期四）下午3:40—4:40
地点：华东师大闵行校区数学系102报告厅

摘要
In this talk, we concentrate on the geometric properties of solutions to magnetic Schrodinger equations.
Firstly, we study the critical set of a complex-valued solutions to a Schrodinger equation involving the magnetic field and with a nonlinear term. We consider this equation in a bounded domain with Neumann boundary condition, and we establish a global 1-dimensional Hausdorff measure estimate for the critical set.
Secondly, we continue on the research of the nodal set to the solution, which also satisfies magnetic Schrodinger equation. Under some quasi-conformal conditions, we obtain a local 1-dimensional Hausdorff measure estimate to the nodal set.
Finally, we will talk about some topology of the nodal set, i.e. the Betti number. Compared with the result on polynomial, we consider the case of a general second-order elliptic equation. We establish an estimate on the total Betti number of second-order elliptic PDEs.

2011年05月06日

题目：Modulation of gene transcription noise by signal transduction pathways

报告人：唐谟勋教授（Moxun Tang）
Department of Mathematics, Michigan State University

日期：5月12日 （周四） 下午 3:40 - 4:30

地点：闵行数学楼102报告厅

ABSTRACT: Each of us is made of 50 to 75 trillion cells. The cells in our hearts are apparently different from the cells in our eyes, but yet they contain the same set of approximately 23,000 protein-coding genes. Gene transcription is a central cellular process that determines if, when, and to what extent, genes will be expressed, and ultimately defines the cell's identity. Given the magnificent precision of our body plan, it is intriguing to know that gene transcription is a stochastic process. It remains largely unknown how cells balance their functional fidelity and the transcription noise. We approach this question through mathematical modeling that combines differential equations and methods in renewal theory. Our analysis predicted several mechanisms by which genes could stay away from abnormally noisy transcription while living with multiple cross-talking signal transduction pathways. The most efficient mechanism is to maintain a relatively long elongation duration by transcription pausing, interrupting, or back-tracking. Alternatively, high noise strength is prevented if all the signaling pathways activate transcription strongly. If one pathway activates transcription much weakly than others, then low noise is ensured if the cells shut down this noise-making pathway, or, to our big surprise, use it even more frequently.

2011年05月04日

报告人：叶东 (D.Ye)教授 （Univ. of Metz, France）

时间：2011年5月6日(周五)下午1:00 — 2：00

地点：闵行校区数学楼102报告厅

报告题目: A Hardy-Moser-Trudinger inequality

2011年05月04日

曹锡华代数论坛

报告人：Steven Lu教授 （魁北克大学蒙特利尔分校）

时间：2011年5月4日(周三)下午15:00-16:00

地点：闵行校区数学楼102报告厅

一般型非正则簇的特殊子簇

Special subvarieties of irregular varieties of general type

Abstract

Special varieties are generalizations to higher dimensions of the curves C,CP^1, C^* and elliptic curves. We will bound the family of special subbvarieties of a variety with maximal Albanese dimension (a variety characterized by generically finite quasi-Albanese map) in terms of the positive part of the log-canonical polarization of the variety. This verifies, for such a variety, a conjecture of Lang on the algebraic pseudo-hyperbolicity of varieties of log general type. In particular, for quasiprojective surfaces of log general type and log irregularity two or more, we obtain the finiteness of special curves (such a curve is one whose normalization is CP^1 minus at most two points or an elliptic curve) in such a variety.

2011年05月03日

《曹锡华代数论坛》报告

报 告 人: 赵开明 教授
(加拿大Wilfrid Laurier University, 中国科学院数学所)

报告题目: N-point Virasoro algebras.

报告内容： In this talk I will introduce and study $n$-point Virasoro algebras, $V_a$, which are natural generalizations of the classical Virasoro algebra and have as quotients multipoint genus zero Krichever-Novikov type algebras. The necessary and sufficient conditions for the later two such Lie algebras to be isomorphic will be given. Moreover we determine their automorphisms, their derivation algebras, their universal central extensions, and some other properties. The list of automorphism groups that occur is $C_n$, $D_n$, $A_4$, $S_4$ and $A_5$. This is based on a joint work with Ben Cox, Xiangqian Guo and Rencai Lu.

时间：2011/5/9(周一)， 上午10点-11点

地点：闵行校区数学系一楼主报告厅

2011年05月03日

报告人：管克英教授 （北京交通大学）
时间：2011年5月10日(周二)下午1:50 — 2：50
地点：闵行校区数学楼102报告厅

报告题目：平面流体Euler方程的一个精确解

内容简介：用新提出的”伪势”方法给出Euler方程的一个精确解, 该解为一个平面流体速度场，而它又定义了一个平面周期哈密顿系统。通过KAM理论及二阶Melnikov函数可以说明该精确解确能描述流体的复杂运动，如动态漩涡、布朗运动、扩散与渗透等现象。

2011年04月28日

数学系--偏微分方程中心联合讨论班
Department of Mathematics- Center for PDE
Joint Seminar

报告题目: Newtonian Potential in a Relative Sense
演讲人： Professor Yong Jung Kim
Korean Advanced Institute of Science and Technology
时间： 2011年4月27日（星期三）下午3:00—4:00
地点： 华东师大闵行校区数学系102报告厅

摘要
It has been believed that the mobility of a species helps its survival. However, a recent analysis on a competition model shows an opposite result that the slower diffuser prevails. This rather paradoxical conclusion is because the purpose for having bigger mobility is missing. We will show in this article that, if the mobility of a species is increased when the resource is not enough, this species may prevail other ones which are not. It is not just a bigger mobility, but the purpose to have a bigger mobility that gives the edge in the competition. The new competition model in this article employs a biological pressure.
Purpose (From Matrix Reloaded) ``There's no escaping reason, no denying purpose, because as we both know, without purpose, we would not exist. It is purpose that created us, purpose that connects us, purpose that pulls us, that guides us, that drives us, that binds us. It is purpose that defines us. We are here because of you, Mr. Anderson. We are here to take from you what you tried to take from us. Purpose."
Purpose (Revised) "There's no diffusing reason, no negative purpose, because as we both know, without purpose, we would be extinct. It is purpose that makes us survive, purpose that regularizes us, purpose that singularizes us, that convects us, that fluxes us, that aggregates us. It is purpose that defines us. We are here because of you, Slower Diffuser. We are here to take from you what you tried to take from us. Resources."

2011年04月13日

曹锡华代数论坛

报告人：江迪华教授（美国明尼苏达大学）

时间：2011年4月13日（星期三）上午10:00—11:00

地点：华东师范大学闵行校区数学系102报告厅

报告题目：

Construction of Endoscopy Correspondences for Classical Groups

摘要：

The endoscopy structures of discrete spectrum of automorphic forms for classical groups was discovered by the stable trace formula approach to establish certain Langlands functoriality. The recent proof of the Fundamental Lemma and its variants by Ngo and others made it possible to establish the existence of the endoscopy transfers for classical groups by Arthur stable trace formula.

In this talk, we report on my recent work joint with David Ginzburg and David Soudry, which gives integral transforms which explicitly construct certain families of endoscopy transfers for classical groups. The integrals are made of residues of certain Eisenstein series.

2011年04月12日

运筹学与控制论组学术报告

题 目：A Vertex Ordering Characterization of Asteroidal
Triple-free (AT-free) Graphs

报告人：Professor Derek G. Corneil
Department of Computer Science
University of Toronto,Canada

时 间：2011年4月12日 上午10:00-10:50

地 点：华东师大闵行校区数学系102报告厅

报告内容简介：Many families of graphs have a vertex ordering characterization that plays an important role
in various algorithms (often based on graph searching) for graphs in the family. Examples
include unit inverval graphs, interval graphs, and cocomparability graphs. Note that an asteroidal
triple is an independent triple of vertices, S, such that between any two vertices in S there is a path
that avoids the neighbourhood of the third vertex in S. AT-free graphs strictly contain the families
of graphs mentioned above, and it has long been questioned whether AT-free graphs also have
such a characterization. An early attempt to solve the problem lead to the discovery of path-orderable graphs, a family that lies strictly between cocomparability graphs and AT-free graphs.
This talk presents a recent vertex ordering characterization of AT-free graphs;
note that similar characterizations hold for graphs of bounded asteroid number.
The talk concludes with open questions, especially pertaining to the search for graph search
based algorithms for AT-free graphs.
[Joint work with Juraj Stacho]

2011年04月08日

题 目: The $n × (n-2) $ Local Converse Theorem for GL(n) Over p-adic Field
报告人： 粘珠凤 副教授 （台湾国立成功大学）
时 间: 2011年4月8日（星期五） 上午：10:00-11:00
地 点: 闵行校区数学系126室

摘 要：
The $n × m$ local converse theorem states: Let $\pi_1$, $\pi_2$be irreducible supercuspidal representations of GL(n, F), where F is a p-adic field. If the twisted local $\gamma$-factors are the same, i.e. $\gamma(s, \pi_1, \tau)=\gamma(s, \pi_2,\tau) $ for all irreducible supercuspidal representations $\tau$ of GL(k,F) with k = 1,2,…m, then $\pi_1$ and $\pi_2$ are equivalent.

This theorem characterizes the supercuspidal representations of GL(n,F) in terms of their \gamma-factors. A conjecture named after Jacquet predicts the verity of the $n × m$ local converse theorem for m=[n/2].

In this talk we will introduce Jeff Chen's work : The $n×(n-2)$ local converse theorem for $GL(n,F),$ which extends Henniart's result on $n×(n-1)$ local converse theorem (1993).

2011年04月04日

报告人：尹永成 教授（浙江大学）
时间： 4月4日 上午10:30-11:30
地点： 中山北路校区理科A楼1510室
报告题目：Regularity of bounded critical Fatou components for polynomials.
摘要：Let $U$ be a bounded critical Fatou component for a polynomial.
(1). If $U$ is attracting and its boundary contains neither parabolic points nor recurrent critical points, then $U$ is a quasidisk.
(2). If $U$ is parabolic associate with a paraboloc point $p$ and $\partial U\{p}$ contains neither parabolic points nor recurrent critical points, then $U$ is a John domain. Moreover, if there are at least two petals, then $U$ is a quasidisk.

2011年04月04日

报告人：崔贵珍 研究员（中国科学院数学与系统科学研究院）
时间： 4月4日 上午9:00-10:00
地点： 中山北路校区理科A楼1510室
报告题目：Foldings of polynomials
摘要： We study post-critically finite branched coverings
such that they have a non-peripheral Jordan curve whose pre-image
contains at least two Jordan curves and each of them is homotopic to
itself rel the post-critical set. We give conditions under which
they have no Thurston obstruction. In particular we construct
hyperbolic rational maps whose Julia sets are Sierpinski carpet. We
also provide an example for the above branched coverings with a
Thurston obstruction.

2011年03月24日

台湾中央研究院数学研究所程舜仁教授3小时系列学术演讲
演讲题目：Central characters of Lie superalgebras of classical type and symmetric functions （II）
时间：2011年3月24日（周四）上午10：00-11：30
地点：闵行校区数学楼102报告厅

2011年03月23日

台湾中央研究院数学研究所程舜仁教授3小时系列学术演讲
演讲题目： Central characters of Lie superalgebras of classical type and symmetric functions （I）
时间：2011年3月23日（周三）下午3：00-4：30
地点：闵行校区数学楼102报告厅

2011年03月22日

数学系--偏微分方程中心联合讨论班
Department of Mathematics- Center for PDE
Joint Seminar

报告题目: Exponential Stability of Large-Amplitude Traveling Fronts for Quasi-linear Relaxation Systems with Diffusion
演讲人：王丽娜 博士（首都师范大学）
时间：2011年3月22日（星期二）下午3:40—4:40
地点：华东师大闵行校区数学系102报告厅

摘要：
In many physical problems such as in traffic flow and shallow water flow, both relaxation and diffusion are involved. In this talk, we are interested in the stability of traveling front solutions for 2 times 2 quasi-linear relaxation systems with small diffusion rate. By applying geometric singular perturbation method, special Evans function estimates, detailed spectral analysis and C_0 semigroup theories, we prove that all the non-degenerate waves for semi-linear relaxation systems are locally exponentially stable in some exponentially weighted spaces. We also obtain the linear exponential stability of the non-degenerate waves for quasi-linear relaxation systems, where the wave strengths can be large.

2011年03月22日

题 目： Some partition problems on graphs

报告人：Professor Jing Huang (黄靖教授)
Department of Mathematics and Statistics
University of Victoria，Canada

时 间：2011年3月22日 上午10:00-10:50

地 点：华东师大闵行校区数学系102报告厅

摘要：Polarity and monopolarity are properties of graphs defined in terms of the existence of certain vertex partitions, which are hard to recognize in general. It has been shown however that, among several classes of graphs such as cographs, chordal graphs, and line graphs, both properties are recognizable in polynomial time. In this talk we address the two recognition problems for claw-free graphs, arguing that the recognition of the polarity is in essence of the satisfiability problem and hence an NP-complete problem and the recognition of monopolarity is solvable in polynomial time. Thus claw-free graphs demonstrate a contrast between the two problems. The polynomial time algorithm for recognizing monopolar claw-free graphs resembles the well-known breadth first search algorithm and is based on a structural characterization of the graphs. This work is joint with Ross Churchley.

2011年03月17日

华东师范大学数游天下协会数模部特邀刘永明教授在图书馆报告厅举办数学建模学术讲座

时间：2011年3月17日，星期四，18:00～20:00

地点：华东师大闵行校区图书馆111报告厅

主讲人：刘永明教授

讲座主题：
1.揭开数学建模的神秘面纱，普及数学建模知识。
2.数学建模各类技巧讲解，不一样的数学建模，更精妙的思路。
3.华师大数学系作为主办方，对华东地区数学建模竞赛进行动员。

Plus：互动环节有精美礼品相送

参加对象：不限

数学系
2010-03-11

2011年03月15日

数学系--偏微分方程中心联合讨论班
Department of Mathematics- Center for PDE
Joint Seminar

报告题目: Asymptotics of the interface of a Hele-Shaw flow with multiple point sources
演讲人： Dr. Michiaki Onodera
National Taiwan University
时间： 2011年3月15日（星期二）下午1:00—2:00
地点： 华东师大闵行校区数学系102报告厅

摘要

We study the asymptotic behavior of the interface of a Hele-Shaw flow produced by the injection of fluid from finitely many points at different speeds. We prove that, as time goes to infinity, the interface approaches an expanding circle centered at the barycenter of the injection points with weights proportional to the injection rates. The distances from the barycenter to the boundary points are estimated from above and below. The proof is based on a precise estimate of quadrature domains of the measure in the case where a, b>0 and a+b is sufficiently large. Here denote the Dirac measures at i, -i respectively. The definition and basic ideas of quadrature domains will be provided in the talk. Combining an induction argument with the estimate yields the result

2011年03月10日

曹锡华代数论坛

报告人： Ivan Cheltsov 教授 University of Edinburgh

中文题目： 关于 Cremona 群我们所知道的和不知道的

英文题目： What we know and what we do not know about Cremona groups?

时间： 2011年 3月 10 日 （周四） 下午 15：00-16：00

地点： 数学系126 教室





摘要

Cremona group of rank n is the group of birational automorphisms of n-dimensional projective space. The first results about the Cremona group of rank 2 go back to Apollonius of Perga (225-190 BC) who introduced the circle inversion, which is a birational involution of the real projective plane. Now we know a lot about the Cremona group of rank 2. We know its generators (Noether) and relations between them (Gizatulin). We know almost all its finite subgroups (Dolgachev and Iskovskikh), their conjugacy classes, dynamics of elements of infinite order etc. But many questions about the Cremona group of rank 2 are still open. Cremona groups of higher ranks are mistery to us. I will describe what we know about the Cremona group of rank 2, what we know about the Cremona group of rank 3 (recent results), and what we would like to know about them.

2011年03月08日

数学系-偏微分方程中心联合讨论班
Department of Mathematics- Center for PDE
Joint Seminar

报告题目：Standing Waves for Nonlinear Schrodinger Equations with Potentials

演讲人：Dr. Ohsang Kwon, Korean Advanced Institute of Science and Technology, Korea

时间：2011年3月8日（星期二）下午3:40—4:40

地点：华东师大闵行校区数学系102报告厅

摘要：

We consider elliptic equations of the form $\varepsilon _{}^2\Delta u - V(x)u + {u^P} = 0,x \in \Re _{}^N$ whose solutions correspond to semiclassical standing waves for nonlinear Schrodinger equations. The potential V (x) is a determining factor in the existence of solutions and their forms. In this talk, we prove the existence of solutions concentrating around nondegenerate critical points of V which vanishes at infinity. And we investigate the condition of potentials at infinity for the existence of solutions of elliptic systems.

2011年03月08日

图像处理学术报告

报 告 人：台雪成 教授（University of Bergen, Noway and Nanyang Technological University, Singapore）

报告题目：Nonlinear PDEs on manifold for computer vision

报告时间：2011年3月8日（星期二） 下午：2:00-3:00
报告地点：闵行校区数学楼报告厅102

报告简介：
In this talk, we will present several nonlinear partial differential equation on surfaces used for computer vision. The equations include the Beltrami flow, total variation flow, Perona-Malik flow, harmonic map and p-harmonic maps on surfaces. Finite volume will be used to discretize the equations. Some of these equations do not have uniqueness and stability under the continuous setting. We prove that the discretized equations have existence, uniqueness and continuous dependence of initial data. Some numerical experiments will be given to show the applications of these equations for processing and analysis of images on surfaces.

This talk is based on joint work with Chunlin Wu, Falai Chen and Jinsong Deng.

2011年02月28日

报告人：Wing Suet Li 教授 （美国Georgia Institute of Technology）
题目：Intersection of subspaces and Horn inequalities for the eigenvalues of sums of selfadjoint operators
时间：2月28日（周一）下午3点
地点：闵行数学楼102报告厅

摘要： Let A, B, C be n by n selfadjoint matrices. It was conjectured by Horn in 1962 that the relation A+B+C=0 can be characterized by a set of inequalities (Horn inequalities) together with the trace equality. The conjecture was proved in the late 1990s due to the work of Klyachko, Knutson and Tao, using highly sophisticated tools from algebraic geometry. In this talk we will discuss some basic ideas on the intersection of subspaces that will lead to inequalities of the eigenvalues of sums of selfadjoint operators, which leads to an elementary proof of the Horn inequalities that can be generalized to finite Von Neumann algebras (where algebraic geometry tools are totally missing).

报告人简介：Li 教授在Iowa大学读本科，在Michigan大学获博士学位，现为Georgia工学院数学教授，研究领域是泛函分析特别是算子理论和算子代数，以及控制论。Li 教授在一个旨在促进妇女参与科学和工程的项目中工作了5年。 她愿意在本次报告之后和我系的女教师和研究生见面，谈论女性所面临的特殊问题。

2011年02月28日

曹锡华代数论坛

报告人： Mina Teicher 教授 以色列 Bar Ilan Univsity

中文题目： 论线排列的补空间

英文题目： On complements of line arrangements

时间： 2011年 2月 28 日 （周一） 下午 13：30-14：30

地点： 闵行数学楼102 报告厅

摘要

Line arrangements appear in geometry, topology, combinatory, graph theory and applications. We will discuss the topological vs the combinatorial properties and the application to classification of algebraic surfaces

2011年02月25日

题 目: Bifurcation from infinity for the one-dimensional asymptotically linear NLS
报告人： Prof. Francois Genoud
（Heriot-Watt University, Edinburgh, Scotland）
时 间: 2011年2月25日(周五) 下午 1:00 - 2:00
地 点: 闵行校区数学楼102报告厅
摘 要：
I will speak about a (stationary) nonlinear Schrodinger equation arising in the physics of nonlinear planar waveguides. The nonlinearity is formally
asymptotically linear, describing the saturation of the refractive index of the waveguide at high power. However, due to the unboundedness of the domain, the
problem is not rigorously asymptotically linear and a truncation argument is required to carry out the bifurcation analysis. Furthermore, a lack of
regularity and compactness prevents from using standard global bifurcation theory and I appeal to recent developments of degree theory to obtain global,
asymptotic, bifurcation.

2011年01月25日

报告题目： Augmented Lagrangian method for generalized TV-Stokes model for image processing and computer vision

报告人：台雪成 教授 ( Prof. Xue-cheng Tai )
挪威Bergen大学数学系教授 (主要职位)
新加波Nanyang Technological University副教授

时间：2011年1月25日（星期二）上午： 10:00 – 11:30

地点： 中山北路校区理科大楼A座1510室

Abstract：
In this paper, we propose a general form of TV-Stokes models and provide an efficient and fast numerical algorithm based on the augmented Lagrangian method. The proposed model and numerical algorithm can be used for a number of applications such as image inpainting, image decomposition, surface reconstruction from sparse gradient, direction denoising, and image denoising. Comparing with properties of different norms in regularity term and fidelity term, various results are investigated in applications. We numerically show that the proposed model recovers jump discontinuities. Some of the results are based on joint work with C. Wu, J. Hahn and Y. Duan.

2011年01月12日

报告题目：From Fibonacci Numbers to Central Limit Type Theorems

报 告 人: Yinghui Wang (Massachusetts Institute of Technology)

时 间:1月12日（星期三）10:00—11:00

地 点：数学楼102报告厅

摘 要：A beautiful theorem of Zeckendorf states that every integer can be
written uniquely as a sum of non-consecutive Fibonacci numbers
$\{F_n\}_{n=1}^{\infty}$. Lekkerkerker proved that the average number
of summands for integers in $[F_n, F_{n+1})$ is $n/(\varphi^2 + 1)$,
with $\varphi$ the golden mean. We prove the following massive
generalization: given nonnegative integers $c_1,c_2,\dots,c_L$ with
$c_1,c_L>0$ and recursive sequence $\{H_n\}_{n=1}^{\infty}$ with
$H_1=1$, $H_{n+1} =c_1H_n+c_2 H_{n-1} + \cdots +c_ _1+1$ $(1\le n< L)$
and $H_{n+1}= c_1H_n+c_2 H_{n-1}+\cdots +c_L H_{n+1-L}$ $(n\geq L)$,
every positive integer can be written uniquely as $\sum a_iH_i$ under
natural constraints on the $a_i$'s, the mean and the variance of the
numbers of summands for integers in $[H_{n}, H_{n+1})$ are of size
$n$, and the distribution of the numbers of summands converges to a
Gaussian as $n$ goes to the infinity. Previous approaches were number
theoretic, involving continued fractions, and were limited to results
on existence and, in some cases, the mean. By recasting as a
combinatorial problem and using generating functions and
differentiating identities, we surmount the limitations inherent in
the previous approaches.

Our method generalizes to a multitude of other problems. For example,
every integer can be written uniquely as a sum of the $\pm F_n$'s,
such that every two terms of the same (opposite) sign differ in index
by at least 4 (3). We prove similar results as above; for instance,
the distribution of the numbers of positive and negative summands
converges to a bivariate normal with computable, negative correlation,
namely $-(21-2\varphi)/(29+2\varphi) \approx -0.551058$.

2011年01月10日

报告题目：Modeling the Transmission Dynamics and Control of Some Infectious Diseases in China
报 告 人: Shigui Ruan (University of Miami)
时 间:1月10日（星期一）10:30—11:30
地 点：数学楼102报告厅

Abstract. The spread of many infectious diseases can be modeled by
mathematical equations according to certain idealized physical laws. The
physical laws are described in terms of parameters. The basic reproduction
number (R0) is an important concept in studying the transmission and
control of infectious diseases which is defined as the expected average
number of secondary cases produced by an index case during its
infectiousness period. Roughly speaking, a disease can be controlled or
even can die out if R0<1; it spreads out or becomes endemic if R0>1.
Mathematical modeling and analysis plays a crucial role in evaluating R0
in terms of model parameters and understanding the spread of the diseases.
In this talk, we will introduce some basic epidemic models and some recent
work on modeling hepatitis B virus, schistosomiasis, and rabies in China.

2011年01月08日

题目：Nonsmoothable involutions on 4-manifolds

报告人：刘西民， 华南理工大学

地点：中山北路校区理科大楼A座1414

时间：2011年1月8日下午3:00-4:30

2011年01月04日

报告题目：The Geometry of Groups
报 告 人: Yulan Qing (Tufts University)
时 间:1月4日（星期二）10:00—11:00
地 点：数学楼102报告厅

摘 要：We will start with Cayley graph examples and then introduce
infinite spaces on which groups can act geometrically. We give the
concept of an ideal boundary to this space, and shows that this space
is not geometrically independent. The space of interest is the
universal cover of a tori complex, and is also a particular example of
a right-angled Artin group. It is an attempt to address the open
question as to whether right-angled Coxeter groups have unique CAT(0)
boundary. This example could potentially give a negative answer to
the question.

2011年01月04日

题 目: 人民币的基本均衡汇率
报告人：郑伟安 教授 （“千人计划”、长江讲座教授）
华东师范大学金融统计学院，
时 间: 2011年1月4日(周二) 下午 3:00 - 4:00
地 点: 闵行校区数学楼102报告厅
摘 要：
我们采用在美国众议院“汇率改革促进公平贸易法案”采用的主要证词中所引用的SMIM模型, 将其所用的国际货币基金组织对2015年的估计数据换成更现实的2011年估计, 推断出人民币不宜继续升值的论断.