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Sino-Russian Mathematics Center-JLU Colloquium

Properties of polynomial maps and two-dimensional Jacobian conjecture

Speaker:Properties of polynomial maps and two-dimensional Jacobian conjecture

Time:2022年10月14日  9:30-10:30 Moscow time

Meeting ID:ZOOM ID:862 062 0549,Code:2022



Abstract: For any two polynomials on two variables with a nonzero Jacobian determinant, there corresponds a polynomial map known as a Keller map. In this talk, the speaker will report 3 properties of Keller maps, which are used to give a proof of the two-dimensional Jacobian conjecture in the speaker’s paper entitled ``a proof of 2-dimensional Jacobian conjecture'' at arXiv:1603.01867.

Bio: Yucai Su is a professor at Tongji University and Jimei University. He has successively worked as a visiting scholar and postdoctoral researcher at Queen Mary and Westfield College, the University of London, Concordia University, and the University of Quebec at Montreal for 7 years. His main research interests include Lie algebras, representation theory and Jacobian problem. In particular, he has studied the Jacobian Conjecture for eighteen years.  He is an editor of Algebra Colloquium and Journal of Mathematical Study, and published over 100 papers in Adv. Math., J. Eur. Math. Soc., Proc. London Math. Soc., Comm. Math. Phys., Math. Z., Israel J. Math., etc.  Recently, using the local bijectivity of Keller maps, he solved the 2-dimensional Jacobian Conjecture.



Speaker:Michael Batanin (Institute of Mathematics of Czech Academy of Science, Charles University, Prague

Time:2022年09月30日 16:30-17:30 

Meeting IDZOOM ID:862 062 0549,Code:2022



Abstract: Operads were introduced at the end of 1960s by Boardman, Vogt and P.May as spaces parametrising multivariable operations and their substitutions. In the 1990's however, it was realised that there are other interesting types of operads such as cyclic and modular operads of Getzler and Kapranov (motivated by TQFT development) and globular n-operads of Batanin parametrising higher categorical compositional structures. In 2015 Batanin and Markl introduced operadic categories in order to develop a consistent theory of operadic like structures. In my talk I explain what operadic category and associated category of operads are and why this is a very rich and useful new algebraic concept.

Bio: The speaker graduated from Novosibisk State University in 1983. He is currently a Senior Researcher at the Institute of Mathematics of Czech Republic, and a Professor of Charles University in Prague. He is specialising in Algebraic Topology, Category Theory, Operads and related topics.



Speaker:张大军 上海大学

Time:2022年09月23日 10:30-11:30 

Meeting ID:腾讯会议:309-266-962


Abstract: 这是一个关于“孤立波”的历史与发展的科普报告。1834年 John Scott Russell首次发现孤立波,1895年Korteweg和de Vries (KdV) 利用KdV方程描述了孤立波现象, 1965年 Kruskal 和 Zabusky在研究Fermi-Pasta-Ulam问题时发现并命名了“soliton” (孤立子), 两年以后Gardner-Greene-Kruskal-Miura 建立了反散射方法(Inverse Scattering Transform), 成为现代可积理论的起点。报告将回顾孤立波与可积系统在前150年(1834-1984)的历史,回顾期间(特别是1968-1984)出现的重要的可积模型以及重要的理论与方法进展。

Bio: 张大军,上海大学数学系教授,博士生导师。主要从事离散可积系统与数学物理的研究,包括离散可积系统的直接方法、多维相容性的应用、空间离散下的可积结构与连续对应等。曾访问Turku大学、Leeds大学、剑桥牛顿数学研究所、Sydney大学等学术机构。先后主持国家自然科学基金面上项目5项。目前担任离散可积系统国际系列会议SIDE (Symmetries and Integrability of Difference Equations)指导委员会委员(2012-)和国际期刊Journal of Physics A编委(2020-)。

Coarse geometry and operator algebras : a minicourse


Speaker:Yeong Chyuan Chung 博士后  Leiden University

Meeting ID腾讯会议:869-2118-6000,密码:3721


Abstract: Coarse geometry involves studying metric spaces by looking at them from far away, and it is important in areas of mathematics such as geometric group theory. In recent times, its interaction with operator algebras has also been an active area of research with applications to problems in topology and differential geometry. In this mini-course, we aim to introduce basic notions in coarse geometry and a class of operator algebras known as Roe algebras. Starting from coarse geometry, we will introduce basic definitions such as coarse embeddings and coarse equivalences, then we will introduce some coarse geometric invariants such as asymptotic dimension and property A. Next, we will introduce Banach algebras and C*-algebras with examples of these, then we will focus on Roe algebras and how they reflect the coarse geometry of the underlying metric spaces. Finally, we will briefly introduce operator K-theory and the coarse Baum-Connes conjecture involving the K-theory of Roe algebras.



Date of Lecture


Name (Title) of Lecture





Number of Participants

Sep 19, 2022

Introduction to coarse geometry: basic definitions and asymptotic dimension



Sep 20, 2022

Introduction to coarse geometry: property A



Sep 21, 2022

Banach algebras and C*-algebras with examples



Sep 22, 2022

Roe algebras I



Sep 26, 2022

Roe algebras II



Sep 27, 2022

Basic operator K-theory



Sep 28, 2022

K-theory of Roe algebras and the coarse Baum-Connes conjecture



Sep 29, 2022

A quick look at a counterexample to the coarse Baum-Connes conjecture





Bio: Yeong Chyuan Chung(钟永权),2017年博士毕业于美国德州农工大学, 主要从事粗几何、L^p算子代数、K-理论的研究。 近年来在J. Funct. Anal.,J. Noncommut. Geom.等杂志上发表多篇高水平论文。



Advanced Numerical Methods with Applications


Speaker:Andrey Dorogovtsev professor(Institute of Mathematics,NAS Ukraine

Meeting ID:Zoom会议 ID:会议号:852 4434 8793,密码:075030

Abstract: This course aims to provide a solid introduction on some advanced numerical methods and its applications. The first part of the course will introduce the definition of local times and Gaussian functionals, then discuss some properties when local times as a Gaussian functionals. And the second part of the course is devoted to introduce Hausdorff measure and dimension, then use the Hausdorff measure and dimension to discuss sef-intersections set of Brownian motion. Professor Andrey will give students some time to understand the knowledge and give some small questions about the lecture.


Date of Lecture


Name (Title) of Lecture


Duration (Beijing Time)


Number of Participants


Local times and sets of values of random fields




Gaussian white noise and functionals from it




Local times as a Gaussian functionals




Local nondeterminism for Gaussian random fields




Hausdorff measure and dimension




Haussdorf dimension for sef-intersections set of Brownian motion



Bio: Andrey Dorogovtsev教授是乌克兰国家科学院通讯院士,乌克兰国家科学院数学所随机过程理论系主任,主要从事概率论及其相关领域研究,是乌克兰概率论研究方向学术领军人物之一。Andrey Dorogovtsev教授是乌克兰与德国、乌克兰与俄罗斯等国家联合项目的乌方负责人。同时,Andrey Dorogovtsev教授是《Theory of Stochastic Processes》《Ukraine Mathematical Journal》等杂志的编委。

Noncommutative differential geometry and quantum effects of gravity



Time:2022年09月16日 10:30-11:30

Meeting ID:腾讯会议 ID:602-653-169


Abstract: We provide a rigorous theory of noncommutative metrics and curvatures in frame of deformation quantization. In terms of them, we are able to propose the noncommutative Einstein field equations. We show that the deformation of classical pp-waves are exact solutions of vacuum field equations. We also find that the quantization of spherically symmetric metrics is renormalizable and the deformation of classical Schwarzschild solution is the quantum black hole solution which does not depend on time and can not be evaporated. The talk is based on the early joint works with Chaichian, Tureanu, D. Wang, R.B. Zhang as well as H. Gao recently.

Bio: 张晓,中国科学院数学与系统科学研究院数学研究所研究员,国家杰出青年基金及中科院百人计划获得者。现任广西大学君武学者和广西八桂学者,广西数学研究中心执行主任。从事广义相对论的数学研究,在广义相对论正能量问题及引力量子化的非交换几何理论上作出了系统性的贡献。


Higher algebraic structures-a minicourse


Speaker:Camilo Andres Angulo Santacruz(Universidade Federal Fluminense)

Meeting ID:ZOOM ID:862 062 0549   Password:2022



Course Abstract:“Higher structure” is a term used loosely to refer to a large collection of structures that share a common theme. Suppose a mathematical structure consists of a collection of sets, functions between them, and some equations that the latter shall verify. Think of group structures, for instance, as the sets G, GxG, and the singleton, together with three functions (the multiplication, the unit, and the inverse) that verify the usual axioms of a group, which are equations relating them(!). The common idea behind higher structures is that they roughly are like mathematical structures, but replacing sets by homotopy types, equations by homotopies, and adding higher-order homotopies to enforce coherence.

Higher structures have an intricate history and abound in mathematics. We will focus on three types of higher structures that have algebraic flavor.In what follows we describe the plan of the lectures. We will start by giving a bit of a panoramic perspective on the history and emergence of the higher structures we will consider. After going through some preliminaries, we proceed to study them one by one, starting with the so-called L-infinity algebras, continuing with stacky groupoids, and closing with Lie n-groupoids. In each module, we go through definitions, examples, and main constructions. We conclude by trying and relating these structures among them and by giving an outlook for the directions in which these generalize by touching upon some recent research topics.

Bio:Camilo Andres Angulo Santacruz is a post doctor from Universidade Federal Fluminense, Brazil. He mainly study Poisson geometry and higher structures.





Time20220909 10:30-11:30

Meeting ID:腾讯会议 ID:737-700-086



Abstract: 不同于通常的孤子(soliton), 怪波(rogue wave/rogon)拥有巨大的能量,也被称为畸形波、巨波、极端波等。它最早出现在深水海洋中,后来人们发现很多自然科学中也存在怪波现象,如光学、Bose-Einstein凝聚态、等离子体物理、大气科学、生物学和金融市场等。从某种意义来说,社会科学中的突发问题也属于怪波范畴。本报告介绍线性和非线性科学问题中怪波的背景、发展和挑战等。另外讨论怪波产生的一些物理机理等。

Bio: 闫振亚,中科院数学院系统所研究员,主要研究可积系统理论、怪波、PT对称、智能数学物理及交叉应用等。2019年获得国家自然科学基金杰出青年基金。


Operators on the universal enveloping algebras and quantisation of the argument shift method


Speaker:Georgy Sharygin(Lomonosov Moscow State University)

Time20220909 21:00-22:00

Meeting ID:ZOOM ID:862 062 0549   Password:2022



Abstract:  Argument shift method is an important and simple method to generate large commutative subalgebras in Poisson algebras, in particular in the algebras of functions on coadjoint representation of a Lie algebra. In the last 20 years a considerable in finding "quantized version" of such algebras was achieved: in the papers of Rybnikov, Molev and others one can find many examples of commutative subalgebras in the universal enveloping algebras of different Lie algebras, that "raise" the subalgebras, obtained by the argument shift method. However these subalgebras are constructed by "quantizing" concrete sets of generators in the "classical" argument shift subalgebras, and no general construction of "shifting" in the universal enveloping algebras is known. In my talk I will discuss a potential "quantum counterpart" of the shift in a particular case of the Lie algebra gl_n. It is based on the use of "quasi-derivations" of Ugl_n, introduced by Gourevitch and Saponov. I will describe these operators and discuss their relation with other constructions. I will also discuss the experimental data that supports the conjecture that one can define the quantum shift of the argument using these operators.  

Bio: Georgy Sharygin got his PhD from Moscow State University in 2000, and since that time he has been teaching Mathematics at all levels from High school to the PhD programs. He was invited speaker at many international conferences, was many times invited researcher in various international institutes. His research interests include deformation quantisation, non commutative geometry, topology, differential geometry and integrable systems.


The category of 2D rational CFT's



Time20220902 21:00-22:00

Meeting ID:腾讯会议 ID:939-656-494


Abstract:  In this talk, I will review the categorical study of 2D rational CFT's and topological defects in the last two decades. In the end, I will show how to use it to describe the category of 2D rational CFT's.  

Bio: 孔良,南方科技大学深圳量子科学与工程研究院研究员。1994年于中国科学技术大学获得物理学士学位,2005年于美国Rutgers,the State University of New Jersey获得数学博士学位。主要研究拓扑量子场论和共形场论的数学理论,以及在拓扑物质态中的应用。





Time20220819 10:00-11:00

Meeting ID:腾讯会议 ID:721-493-311                           



Abstract:  这是关于Darboux变换的一个科普报告。我们将从Jean Gaston Darboux发表于1882年一篇短文谈起,介绍什么是Darboux变换、构造Darboux变换的方法以及它在可积系统理论中的应用。

Bio: 刘青平,国务院政府特殊津贴获得者,北京市高等学校教学名师,1992年获英国Leeds大学博士学位,曾在中国科学院理论物理研究所和西班牙Complutense大学做博士后,现为中国矿业大学(北京)教授。从事可积系统理论及其应用研究。更多信息见个人主页:https://lxy.cumtb.edu.cn/info/1067/1238.htm





Time2022年08月12日 10:00-12: 00

Meeting ID:腾讯会议 ID:324-276-209


Abstract:  Morse指标定理源于对测地线的研究,它将Morse指标表为测地线共轭点的重数之和。在本次演讲中我们将回顾Morse指标定理的经典结论并介绍最新的进展。 

Bio: 胡锡俊,山东大学教授。1997年7月和1999年7月在吉林大学分别获得学士学位和硕士学位,2002年7月在南开大学获得博士学位。2014年获得国家杰出青年基金,主要研究方向为哈密顿系统与非线性分析。在天体力学中周期解的稳定性问题,哈密顿系统指标理论及一类反应-扩散方程行波解的研究中做出了创新性的工作。


Symmetries: from groups to tensor categories


SpeakerAlexei Davydov(Ohio University

Time2022年08月12日 16:00-17: 00

Meeting ID:ZOOM ID:862 062 0549, Password:2022



Abstract: Groups are mathematical ways of talking about symmetries. From its beginning Group Theory was driven by the idea of symmetry and its applications (e.g. Galois' proof of unsolvability of a quintic). One of the most spectacular applications of Group Theory was the classification of crystals done at the end of the 19th century. In the middle of the 20th century Group Theory was used to describe all known states of matter. Experimental developments of the condensed matter physics at the end of the 20th century were not fitting the standard Group Theory scheme. They forced us to generalize the mathematical formulation of symmetry. The talk will be about this generalized notion, the one of tensor category.  

Bio: Alexei Davydov is a Professor of Department of Mathematics, Ohio University. He mainly works on category theory and homological algebra.

Gravity properad, moduli spaces M_g,n, and string topology

Speaker:Sergei Merkulov   University of Luxembourg

Time2022年08月05日 16:00-18: 00

Meeting ID:ZOOM ID:862 062 0549




Abstract: Using Thomas Willwacher’s twisting endofunctor, and Kevin Costello’s theory of partially compactified moduli spaces of algebraic curves of arbitrary genus with marked points, we introduce a new dg properad which contains Ezra Getzler’s operad controlling genus zero moduli spaces. We discuss its applications in the theory of moduli spaces M_g,n, and in string topology.  

Bio: Sergei Merkulov is a Professor at the University of Luxembourg. He worked previously at the Russian Academy of Sciences, the Glasgow University (UK) and the Stockholm University (Sweden). He works on category theory, homological algebra and Differential geometry.

Thick morphisms of supermanifolds and homotopy algebras

Speaker:Theodore Voronov   University of Manchester

Time2022年07月29日 16:00-18: 00

Meeting IDZOOM ID:862 062 0549




Abstract: Supergeometry can be used as a unifying language for many algebraic and differential-geometric constructions. Particular role here is played by homological vector fields, i.e. odd vector fields Q satisfying Q^2=0. They can be useful for describing “higher” or “homotopy” analogs of Poisson brackets. Recently I discovered a generalization of the notion of a smooth map (called by me “thick morphisms”) giving NONLINEAR pullbacks on smooth functions. “Thick morphisms” can in particular provide L_infinity morphisms for homotopy Poisson structures. There are other interesting connections, e.g. with Fourier integral operators. Thick morphisms also provide a nonlinear analog of classical functional-algebraic duality.   

Bio: Dr Theodore Voronov is a Professor in Pure Mathematics at the University of Manchester (UK). His research interests are on the crossroads of algebra, differential geometry, topology and mathematical physics; in particular, geometry of supermanifolds and its applications. See more at 





Representations of the Fermion-Virasoro algebras 

Speaker:赵开明 Wilfrid Laurier University


Time2022年07月15日 09:00-11:00

Meeting ID

腾讯会议 ID:635-613-814





Abstract: We introduce Fermion algebras F and the Fermion-Virasoro algebras. They are infinite-dimensional Lie superalgebras. The progress on simple smooth modules and simple Harish-Chandra modules over these algebras will be discussed.

Bio: 赵开明,加拿大Wilfrid Laurier大学教授,主要研究方向为李代数。主持多项国家自然科学基金, 及加拿大NSERC基金。他在 Adv. Math., Tran. AMS, J. Lond. Math. Soc., J. Algebra 等国际刊物上发表学术论文100多篇。

Rota-Baxter bisystems and mixed bialgebras 


Speaker:Abdenacer MakhloufUniversité de Haute Alsace

Time20220708 16:00-17:00

Meeting ID

ZOOM: 862 062 0549,Password: 2022

To Join Zoom Meeting:


Abstract: In this talk, we deal with a generalization of the concept of Rota-Baxter operators defined by T. Brzezi´nski and called Rota-Baxter systems which appeared in [J. Algebra 460(2016):1- 25]. We provide a dual version and then consider a generalization to bialgebras, we introduce the notion of Rota-Baxter bisystem and construct various examples. On the other hand, we introduce a new type of bialgebras (named mixed bialgebras) which are consisting of an associative algebra and a coassociative coalgebra satisfying the compatible condition determined by two coderivations. We investigate coquasitriangular mixed bialgebras and the particular case of coquasitriangular infinitesimal bialgebras, where we give the double construction. This is a joint work with Tianshui Ma and Sergei Silvestrov.

Bio: Abdenacer Makhlouf is a Professor and the head of Mathematics Department at University of Haute Alsace, Mulhouse, France. His research covers structure, representation theory, deformation theory and cohomology of various types of algebras, including Nonassociative algebras, Hopf algebras and n-ary algebras.


Kahler-Ricci flow on smooth minimal models 



Time20220701 10:00-12:00

Meeting ID腾讯会议 ID:780-765-137

To Join Tencent Meeting: https://meeting.tencent.com/dm/5cjuobQFgOpb 

AbstractIt is a survey talk on the long-time behavior of a Kahler-Ricci flow on a smooth manifold with a semi-ample canonical line bundle.





Time20220624 14:00-16:00

Meeting ID:腾讯会议 ID:703-956-224

To Join Tencent Meetinghttps://meeting.tencent.com/dm/gtlAO1KvxQLo


Bio徐晓平,中国科学院大学教授,中国科学院数学研究所所长。1992年在美国Rutgers大学取得博士学位,师从著名的李理论专家James Lepowsky Robert Lee Wilson。之后在香港科技大学工作十年。2002年回到中国科学院数学研究所工作, 2014年开始兼任中国科学院大学教授,自20223月起,任中国科学院数学研究所所长。获宝钢优秀教师奖。他在李代数、顶点算子代数(共形场论)和偏微分方程的代数解法等相关领域的研究中做出了重要贡献。




Time20220624 10:00-12:00

Meeting ID685-963-603

To Join Tencent Meetinghttps://meeting.tencent.com/dm/49Yn9DtKVB4q




Factorization of Shapovalov elements 

Speaker:Andrey MudrovMoscow Institute of Physics and Technology and University of Leicester

Time20220617 15:00-17: 00

Meeting ID:ZOOM ID:862 062 0549, Password:2022

AbstractA classical result of J. Bernstein, I. Gelfand and S. Gelfand says that a singular vector in a Verma module over a simple complex Lie algebra can be obtained from its highest vector by applying a product of special elements of the negative nilpotent subalgebra called Shapovalov elements. We provide explicit formulas for those elements, and hence for singular vectors of the Verma modules, expressing them through certain matrix elements of the inverse contravariant Shapovalov form.

BioThe speaker is currently an Associate Professor and a Senior Researcher at the Center of Fundamental Mathematics in MIPT, and an Honorary Lecturer at the University of Leicester. He is specializing in quantum groups, deformation quantization and related topics. 




Time20220610 10:00-12:00

Meeting ID564-626-700 

To Join Tencent Meetinghttps://meeting.tencent.com/dm/p7VBNfhblItm


Bio张影,1985.9-1999.5 吉林大学数学系本研学习、任教,1999.5-2004.7 新加坡国立大学读研,2006.3-2007.2 巴西国家数学所(IMPA)博士后,2009.6至今,苏州大学数学科学学院教授。从事几何拓扑学研究。



Speaker:段海豹 (中国科学院数学与系统科学研究院)

Time2022527 10:00-12:00

Meeting ID899-680-387

To Join Tencent Meetingmeeting.tencent.com/dm/Il9TkCVA4hAL

Abstract同调论是20世纪数学所诞生的一项新技术,是当代几何、拓扑、分析学的有力工具。报告通过 Riemann, Poincare, Brouwer, Hopf 等开拓者们的相关工作介绍,回顾同调论的背景、起源、以及发展历程。

Bio段海豹,中国科学院数学与系统科学研究院研究员,19773月-19851月,在吉林大学数学系学习,获理学学士、硕士学位;19877月,在北京大学获博士学位。从事代数拓扑,微分拓扑和代数几何的教学、研究工作。 他在2005年获中国数学会陈省身数学奖,2010年获国家自然科学二等奖。


Lie 2-algebras from geometric structures 

Speaker:Zhangju LIU

Time2022.5.13 14:00-16:00

Meeting ID347-371-151

To Join Tencent Meetinghttps://meeting.tencent.com/dm/rx9v5zMU7xnV

AbstractThe notion of Lie 2-algebras is introduced as categorification of Lie algebras, Which is one of the fundamental objects in higher Lie theory and has close connection with strongly homotopy Lie algebras. The Lie 2-algebra structure has enjoyed significant applications in both geometry and mathematical physics. Strict Lie 2-algebras are equivalent to Lie algebra crossed modules, which are classified by the third cohomology of a Lie algebra.

In this talk, we’ll review several Lie 2-algebras that come from geometric structures, namely, 2-plectic manifolds; Courant algebroids; homotopy Poisson manifolds and affine structures on Lie groupoids. A 2-plectic structure on a manifold is a nondegenerate closed 3-form. There is a Lie 2-algebra structure on functions and Hamiltonian 1-forms of a 2-plectic manifold A Courant algebroid is a vector bundle together with a bilinear form, a skew-symmetric bracket and an anchor map. The bracket satisfies the Jacobi identity up to a coboundary, which generates a Lie 2-algebra on the section space of the bundle and functions on the base manifold. Parallel to the fact that there is a one-to-one correspondence between Lie algebra structures on a vector space and linear Poisson structures on the dual space, there is a one-to-one correspondence between Lie 2-algebra structures on a 2-vector space and linear homotopy Poisson structures on the dual 2-vector space. On a Lie groupoid, vector fields that are compatible with the groupoid multiplication are called multiplicative. Multiplicative vector fields with the Schouten bracket form a Lie algebra, which is not invariant under the Morita equivalence of Lie groupoids. To define vector fields on a differentiable stack, one needs to extend the Lie algebra to a Lie 2-algebra formed by affine vector fields on a Lie groupoid, which is Morita invariant.



Morse matching method for conformal cohomology 

Speaker:Pavel Kolesnikov (Sobolev Institute of Mathematics)

Time2022.5.6 10:00-12:00

Meeting ID862 062 0549


To Join Zoom Meetinghttps://us02web.zoom.us/j/8620620549?pwd=bGhsaG15WjRza2V3ZEN4TzJYZ1FZQT09

AbstractWe will observe the matching method in the algebraic discrete Morse theory which provides us a powerful tool for finding Anick resolutions for associative algebras defined by generators and relations. We apply this method to find reduced Hochschild cohomologies of associative conformal algebras in order to study their relations with the cohomologies of Lie conformal algebras. In particular, we evaluate the Hochschild cohomology groups for the universal associative envelope U(3) of the Virasoro Lie conformal algebra.

BioPavel Kolesnikov got his PhD in 2002 in Novosibirsk State University (NSU) and joined Sobolev Institute of Mathematics. Now he is a research fellow of the Institute and professor in the NSU. His main area of research interests is in the structure and combinatorial theory of associative and non-associative algebras, conformal and vertex algebras.


On the cobar-construction for non-simply connected spaces

Speaker:Andrey Lazarev ( Lancaster University )

Time:2022.04.22 16:00-18:00

Meeting ID862 062 0549


To Join Zoom Meetinghttps://us02web.zoom.us/j/8620620549?pwd=bGhsaG15WjRza2V3ZEN4TzJYZ1FZQT09

AbstractThe cobar-construction produces a differential graded (dg) algebra out of a dg coalgebra. When applied to the coalgebra of simplicial chains on a simply-connected space X, the resulting dg algebra models the chain algebra on the based loop space of X. This is a classical result of Adams and it has been known for over 60 years. In a recent breakthrough development, American mathematicians Rivera and Zeinalian removed the simple-connectivity assumption.  In this talk, I will explain Rivera-Zeinalian’s result, discuss its generalizations and connections with infinity-categories.

BioAndrey Lazarev is a professor of pure mathematics in the University of Lancaster. His recent research deals with homotopy theory of differential graded algebras and categories, derived categories and higher phenomena. It has applications in rational homotopy theory, theory of operads and operadic algebras, algebraic topology and pure algebra. Andrey Lazarev is the Managing Editor of the journalBulletin of the London Mathematical Society》, as well as a Member of the Editorial Board of  the journalHigher_Structures》.


Boson-Fermion Correspondence and Its Applications to Integrable Hierarchies Revisited From The Point of View of Representation Theory and Random Walks

Speaker:Jian Zhou

Time2022.04.15 10:00-12:00

Meeting ID694-475-243

To Join Tencent Meetinghttps://meeting.tencent.com/dm/dbl4pDJLd3zS

AbstractWe revisit the boson-fermion correspondence and its applications to integrable hierarchies via representation theory of symmetric groups. This makes it natural to consider random walks on various diagrams and graphs related to symmetric groups. Random partitions, hypergeometric tau-functions and weighted Hurwitz numbers are then brought together under a unified probabilistic treatment, rooted in their connections to the fermionic Fock space. Various approaches to the representation theory of symmetric groups all turn out to be useful in this treatment. They include: the new approach of Okounkov and Vershik, the Hopf algebra approach of Zelevinsky, and the lambda-ring approach of Knutson. A connection to the interpolating statistics in the study of fractional quantum Hall effect will also be explained.



Heegaard splitting: a survey

Speaker: 邱瑞锋 (华东师范大学)

Time:2022年04月08日 10:00-12:00



Abstract: Heegaard分解是紧致三维流形上普遍存在的组合拓扑结构,在三维流形理论的研究中起到了重要的作用。吉林大学是我国最早从事这一领域研究的研究群体,并直接或间接地培养了一批这一领域的专家学者。这个报告将介绍这一领域的国内外发展历史及现状。



Orbifold theory and modular extensions

Speaker: 董崇英 美国加州大学Santa Cruz 分校

Time:2022-03-25 10:00-12:00 

Abstract: Orbifold theory studies a vertex operator algebra V under the action of a finite automorphism group G.  The main objective is to understand the module category of fixed point vertex operator subalgebra V^G.  We prove a conjecture by Dijkgraaf-Pasquier-Roche on V^G- module category if V is holomorphic. We also establish a connection between rational orbifold theory and minimal modular extensions. Our work is based on the previous results on modular extensions by Drinfeld-Gelaki-Nikshych-Ostrik and Lan-Kong-Wen. This is a joint work with Richard Ng and Li Ren.

Bio: 董崇英,美国加州大学Santa Cruz分校终身教授,国际上无限维李代数和顶点算子代数领域最杰出的数学家之一,多年来一直从事无穷维李代数、顶点算子代数、Orbifold理论以及广义月光等方面的研究。在Acta Math.、Duke Math. J.、Adv. Math.、Comm. Math. Phys.等国际著名期刊发表论文100多篇,总引用超过3000次,其中包括菲尔兹奖获得者Drinfeld、Zelmanov和Borcherds以及著名数学家如Beilinson和Kac等人的重要引用。主持多项美国自然科学基金,并担任杂志Algebra Colloquium的主编以及Science China Mathematics等多个杂志的编委。


Deformations of Symplectic Foliations

Speaker: Marco Zambon (KU Leuven)

Time: 2022.03.04  20:00-22:00


           To Join Zoom Meeting: 


          Meeting ID:862 062 0549



Symplectic foliations and regular Poisson structures are the same thing. Taking the latter point of view, we exhibit an algebraic structure that governs the deformations of symplectic foliations, i.e. which allows to describe the space of symplectic foliations nearby a given one.  Using this, we will address the question of when it is possible to prolong a first order deformation to a smooth path of symplectic foliations. We will be especially interested in the relation to the underlying foliation. This is joint work with Stephane Geudens and Alfonso Tortorella.


Marco Zambon is an associate professor at KU Leuven, Belgium. He works on topics related to Poisson geometry, in particular on those related to foliations, deformations and Lie theory.




Diophantine approximations


SpeakerNikolay Moshchevitin (Moscow State University)


          ID:894 9789 1576


Lecture1. Continued fractions.
2022.01.19, 13:30-15:00

Representation of real numbers as continued fractions. Approximation by convergents, Perron's formula.
Irrationality measure function.
Lagrange and Dirichlet spectra. Minkowski diagonal continued fraction and the related spectrum. Geometry of continued fractions algorithm.

Lecture2. Distribution of Farey fractions.
2022.01.20, 13:30-15:00

Elements of basic number theory. Euler and Moebius functions.
Integral representation of greatest common divisor. Counting the number of reduced fractions in [0,1].
Fraenel's theorem. Relation to Riemann zeta-function.

Lecture3. Farey tree and Minkowski function.
2022.01.26, 13:30-15:00

Stern-Brocot sequences. Minkowski question-mark function.
Salem's theorem on the derivative. Fixed points problem. An analog to Fraenel's theorem.
Fourier-Stieltjes coefficients.

Lecture4.Multidimensional approximation.
2022.01.27, 13:30-15:00

Simultaneous approximation to real numbers. Linear forms close to xero.
Basic laws of approximation. Best approximations and phenomenon of degeneracy of dimension.
Diophantine exponents and Jarnik's inequalities.


Bio:Professor Nikolay Moshchevitin is working at Moscow State University. His research interests include geometry of numbers, geometric theory of Diophantine approximations, ergodic and combinatorial theory of numbers, theory of dynamical systems. He has published more than 70 papers with more than 400 citations. He was awarded the State Prize of the Russian Federation in 1998.


Geometry of Gaussian random curves

Speaker: Andrey Dorogovtsev (Institute of Mathematics,NAS Ukraine)

Time: January 4, 2022 - February 22, 2022

Location: Zoom

          Meeting ID: 858 7772 7123

          Password: 803617


This course aims to provide a solid introduction on the geometry of Gaussian random curves. Since the theory of geometry of Gaussian random curves is based on the concept of Gaussian random process and fields, the first part of the course will be devoted to some properties of this process and fields. And the second part of the course is devoted to discussion of geometry of Gaussian random curves like the Self-intersection local times for planar Brownian motion and the hitting probabilities for planar Broownian motion. Professor Andrey will give students some time to understand the knowledge and give some small questions about the lecture.


Lecture 1: Gaussian random processes and fields. Main examples
In this lecture we give the definition of Gaussian random processes and fields. Also, we will give some examples to understand this.
Lecture 2: Smoothness of Gaussian random fields
In this lecture we discuss the smoothness of Gaussian random fields, and we can get some properties on Gaussian random fields.
Lecture 3: Euler characteristic of the subsets in Euclid space
In this lecture we give the definition of Euler characteristic which in defined on Euclid space, it is topological invariant.
Lecture 4: Rice formula and asymptotic of tales for supremum of Gaussian random fields
In this lecture we give the Rice formula and discuss the asymptotic of tales for supremum of Gaussian random fields.
Lecture 5: Trajectory of Brownian motion as a random curve. Basic properties
In this lecture we discuss the trajectory of Brownian motion and give some basic properties about this.
Lecture 6: Self-intersection local times for planar Brownian motion
In this lecture we discuss the investigation of the local times of self-intersection as the most important geometric characteristics for planar Brownian motion.
Lecture 7: Hitting probabilities for planar Brownian motion
In this lecture we discuss the hitting probabilities and how we use this to describe the trajectory of planar Brownian motion.
Lecture 8: Tube formula for planar Brownian motion
In this lecture we give the Tube formula for planar Brownian motion, and use it to help us learn the trajectory of Brownian motion.


Bio: Prof. Andrey Dorogovtsev is a corresponding member of the National Academy of Sciences of Ukraine and the Head of the Department of the Theory of Random Processes, Institute of Mathematics, National Academy of Sciences of Ukraine. He mainly works on the theory of probability and its related fields. Prof. Dorogovtsev is a leading specialist in the study of probability theory in Ukraine and the Ukrainian principal investigator in several joint scientific programs between Ukraine and Germany, Ukraine and Russia. Also, he is the editor of many scientific journals, including "Theory of Stochastic Processes" and "Ukraine Mathematical Journal".


Knot theory

Speaker: Vassily Olegovich MANTUROV (Moscow Institute of Physics and Technology)

Time: Janurary 6, 2022 - January 30, 2022

Location: Tencent Meeting

          Room Number: 614-9548-1864

          Password: 372633


Lecture 1. Reidemeister moves. Colouring invariants, and the linking number.
2022/01/06 18:00-19:00 (Beijing time)
Abstract: We will introduce diagrams of knots and links. We use the diagrams to build two invariants of links: Coloring invariant and the linking number.


Lecture 2. The Kauffman bracket, the Jones polynomial.
2022/01/09 18:00-19:00 (Beijing time)
Abstract: We will use Kauffman bracket to prove that Jones polynomial is a link invariant.We will compute some examples and prove the Kauffman-Murasugi-Thistlethwaite Theorem.


Lecture 3.  Fundamental group. The knot group.
2022/01/13 18:00-19:00 (Beijing time)
Abstract: We will define a famous link invariant: the fundamental group of the knot complements. We will show that this group is not trivial if the knot is not trivial.


Lecture 4. The knot Quandle is a complete knot invariant.
2022/01/16 18:00-19:00 (Beijing time)
Abstract: Matveev and Joyce defined a knot invariant, the knot quandle.  This is a complete invariant. We can obtain many invariants from the knot quandle, for example, the knot group and coloring invariant.


Lecture 5.  The braid groups
2022/01/20 18:00-19:00 (Beijing time)
Abstract: We define the braid group. The action of the braid group on Aut(F_{n}) is complete.We will also discuss Markov Theorem and Alexander Theorem.


Lecture 6.  The Alexander polynomial.
2022/01/23 18:00-19:00 (Beijing time)
Abstract: We will introduce several ways to define the Alexander polynomial.


Lecture 7.  Vassiliev invariant.
2022/01/27 18:00-19:00 (Beijing time)
Abstract: We will introduce the Vassiliev invariant and prove that “polynomial” invariant are all come from the Vassiliev invariant.


Lecture 8.  Khovanov homology.
2022/01/30 18:00-19:00 (Beijing time)
Abstract: Khovanov homology is a categorification of the Jones polynomial, in the sense that its Euler characteristic is the Jones polynomial.


Bio: Professor Vassily Olegovich Manturov is from Moscow Institute of Physics and Technology. His research interest is low dimensional topology and knot theory.  He has published more than 150 papers and got more than 1500 citations. He got "Professor of RAS" in 2016 and he is one of the Managing Editors of the "Journal of Knot Theory and Its Ramifications". He has published many books, for instance, 《Parity in knot theory and graph-links. Contemporary Mathematics. Fundamental Directions》,《Low-dimensional Topology and Combinatorial Group Theory》,《Virtual Knots. The State of the Art》 and 《Knot Theory》. He held many international conferences, such as "4-th Russian China Russia-China on Knot theory and Related topics" and three International Conferences in the Mathematical Institute (Oberwolfach) on knot theory and low-dimensional topology".







O-operators on Lie infinity algebras

SpeakerJoana Nunes da Costa(University of Coimbra - Portugal)

Time:2021.12.03 16:00-18.00


              ID:862 062 0549


ZOOM meeting:https://us02web.zoom.us/j/8620620549?pwd=NUhCMWpuTG9Od1RMNjhEdkdwTzlsUT09  

Abstract: We define O-operators on a Lie infinity algebra E with respect to an action of E on another Lie infinity algebra. We characterize these operators as Maurer-Cartan elements of a certain Lie infinity algebra obtained by Voronov's higher derived brackets construction. We determine the Lie infinity algebra that controls the deformation of O-operators with respect to a fixed action.

Bio:Joana Nunes da Costa is a professor of University of Coimbra, Portugal. She mainly works on Poisson geometry and mathematical physics.


The Lang-Trotter Conjecture and the Hardy-Littlewood Conjecture

Speaker:Hourong Qin(Nankai University)

Time:2021.11.26  09:00-11.00 

Location:Meeting Tencent

                 Meeting ID:662 784 567



Bio: 秦厚荣教授现任南京大学数学系系主任,江苏国家应用数学中心主任,中国数学会常务理事,中国科学-数学编委,江苏省数学学会第十届,十一届理事长,第十二届监事会主席。1999年获得国家杰出青年基金,2004年受聘教育部长江学者计划特聘教授,首批入选国家“百千万人才计划”(2004年),享受国务院特殊津贴。他的研究方向主要是代数数论和代数K理论。他在同余数这一历史悠久问题上的研究上取得了重要成果;在数域的Tame核、Tate核方面做出了原创性工作,引发了大量后续工作;解决了田野,Browkin等人的多个猜想;在著名的椭圆曲线Anomalous素数的Mazur猜想以及Lang-Trotter猜想的研究中取得了突破。他在J. Reine Angew Math., P. London Math. Soc., Math. Ann. 等国际著名刊物上发表了数十篇论文,研究结果在国际同行中产生了广泛而积极的影响,被国外同行称为“秦的方法”,多次在高水平国际学术会议上作大会邀请报告。

Quantum GIM of N-fold affinization and quantum toroidal algebra


Speaker:Yun Gao(York University)

Time:2021.11.19  09:00-11.00 


                 Meeting ID:862 062 0549


ZOOM meeting:https://us02web.zoom.us/j/8620620549?pwd=NUhCMWpuTG9Od1RMNjhEdkdwTzlsUT09

Abstract: Generalized intersection matrix (GIM) Lie algebras were introduced by Slodowy in the study of elliptic singularity. GIM Lie algebras of N-fold affinization were studied by Berman-Moody, Benkart-Zelmanov and among others. In this talk we will talk about quantum GIM algebras of N-fold affinization and quantum toroidal algebras.

Bio: 郜云教授是加拿大York大学教授,德国洪堡学者。主要研究方向是无穷维李(超)代数、量子群和表示理论。在高维仿射李代数研究领域做出了重要工作。他已在国际一流数学杂志上发表论文50余篇,其中包括两本美国数学会专著(Memoirs of American athematical Society 1997和2002)。


Embedding of Loday algebras into Rota-Baxter algebras

SpeakerVsevolod Gubarev(Sobolev Institute of Mathematics,Novosibirsk State University)

Time:2021.11.12 15:00-17:00 


                 Meeting ID:862 062 0549


ZOOM meeting:https://us02web.zoom.us/j/8620620549?pwd=NUhCMWpuTG9Od1RMNjhEdkdwTzlsUT09

AbstractThe classical Poincare–Birkhoff–Witt states that every Lie algebra injectively embeds into its universal enveloping associative algebra and this enveloping algebra in some sense does not depend on the Lie product (PBW-property). It is known that every Rota–Baxter algebra of weight 0/1 gives rise to a prealgebra/postalgebra. In 2013, it was proved that every pre- or postalgebra injectively embeds into appropriate Rota–Baxter algebra of weight 0 or 1 respectively. We study the structure and the PBW-property of the universal enveloping Rota–Baxter algebra of a pre- and post-Lie algebra.

Bio:Vsevolod Gubarev ,Senior researcher in Sobolev Institute of Mathematics and senior teacher in Novosibirsk State University (both in Novosibirsk, Russia). Area of interest: ring theory.  


Rota-Baxter operators and non-skew-symmetric solutions of the classical Yang-Baxter equation on quadratic Lie algebras

SpeakerMaxim Goncharov (Sobolev Institute of Mathematics,Novosibirsk State University)

Time:2021.11.5 15:00-17:00 


                 Meeting ID:862 062 0549


ZOOM meeting:https://us02web.zoom.us/j/8620620549?pwd=NUhCMWpuTG9Od1RMNjhEdkdwTzlsUT09

AbstractGiven a quadratic Lie algebra, it is well-known that skew-symmetric solutions of the classical Yang-Baxter equation are in one-to-one correspondence with skew-symmetric Rota-Baxter operators of weight zero. In this talk, we will study connections between Rota-Baxter operators of non-zero weight and non-skew-symmetric solutions of the classical Yang-Baxter equation on finite-dimensional quadratic Lie algebras. Particular attention will be given to the case of simple finite-dimensional Lie algebras.

Bio:Maxim Goncharov, Ph.D., Senior research fellow in Sobolev Institute of Mathematics, Associate Professor at Novosibirsk State University.


Revisiting and extending Poisson-Nijenhuis structures


SpeakerHenrique Bursztyn (Instituto Nacional de Matemática Pura e Aplicada)

Time:2021.10.22 08:00-09:00


                 Meeting ID:862 062 0549


ZOOM meeting:https://us02web.zoom.us/j/8620620549?pwd=NUhCMWpuTG9Od1RMNjhEdkdwTzlsUT09

AbstractPoisson-Nijenhuis structures arise in various contexts, such as the theory of integrable systems and Poisson-Lie theory. I will revisit this notion from a new perspective and show how it can be extended to the realm of Dirac structures. I also hope to mention applications to integration problems. The talk is based on joint work with T. Drummond and C. Netto.

Bio:Henrique Bursztyn is a professor of Instituto Nacional de Matemática Pura e Aplicada (IMPA), Brazil. His research interest includes Poisson geomety, Dirac structures, Lie groupoids, Lie algebroids, deformation quantization and mathematical physics. He published more than 70 papers in high level journals, such as Duke Math. J,  J. Reine Angew. Math.,  Compos. Math.,  Comm. Math. Phys.,  Int. Math. Res. Not. IMRN, Adv. Math.  

Renormalization of quasisymmetric functions

SpeakerLi Guo (Rutgers University-Newark)

Time:2021.10.15 09:00


                 Meeting ID:862 062 0549


ZOOM meeting:https://us02web.zoom.us/j/8620620549?pwd=NUhCMWpuTG9Od1RMNjhEdkdwTzlsUT09


AbstractThe Hopf algebra of quasisymmetric functions (QSym) has played a central role in algebraic combinatorics and has broad applications. A natural linear basis of QSym is the set of monomial quasisymmetric functions defined by compositions, that is, vectors of positive integers. Extending such a definition for weak compositions, that is, vectors of nonnegative integers, leads to divergent expressions. This difficulty was addressed by a formal regularization in a previous work with Jean-Yves Thibon and Houyi Yu. Here we apply the method of renormalization in the spirit of Connes and Kreimer and realize weak composition quasisymmetric functions as power series. The resulting Hopf algebra has the Hopf algebra of quasisymmetric functions as both a Hopf subalgebra and a Hopf quotient algebra. It also gives a realization of free commutative Rota-Baxter algebra on one generator by weak quasisymmetric functions and thus addresses a question raise by Rota many years ago. This is a joint work with Houyi Yu and Bin Zhang. 

Bio:  郭锂,美国罗格斯大学纽瓦克分校教授。郭锂博士于兰州大学获学士学位,于武汉大学获硕士学位,于华盛顿大学获博士学位,并在俄亥俄州立大学、普林斯顿高等研究院和佐治亚州大学作博士后。郭锂博士的数论工作为怀尔斯证明费马大定理的文章所引用,并将重整化这一物理方法应用于数学研究。他近年来推动Rota-Baxter代数及相关数学和数学物理的研究,应邀为美国数学会在“What Is”栏目中介绍Rota-Baxter代数,并出版这个领域的第一部专著。研究涉及结合代数,李代数,Hopf代数,operad,数论,组合,计算数学,量子场论和可积系统等广泛领域.


Title:Koszul duality: old and new

Speaker:Andrey Lazarev(University of Lancaster)

Time:2021.10.8 15:00


                 Meeting ID:862 062 0549


ZOOM meeting:https://us02web.zoom.us/j/8620620549?pwd=NUhCMWpuTG9Od1RMNjhEdkdwTzlsUT09


AbstractKoszul duality is a phenomenon occurring in homological algebra and neighbouring fields, such as rational homotopy theory, representation theory, algebraic geometry, operads and operadic algebras. In this talk I will outline a modern approach to deformation theory based on Koszul duality and explain how it can be globalized.  


Bio:Andrey Lazarev is a professor of pure mathematics in the University of Lancaster. His recent research deals with homotopy theory of differential graded algebras and categories, derived categories and higher phenomena. It has applications in rational homotopy theory, theory of operads and operadic algebras, algebraic topology and pure algebra. Andrey Lazarev is the Managing Editor of the journal《Bulletin of the London Mathematical Society》,as well as a Member of the Editorial Board of  the journal《Higher_Structures》.