# Past Colloquia

**Distinguished Colloquium**

Tuesday, August 26, at 3 p.m.

Auditorium SN-2109

**Victor Kac**

Massachusetts Institute of Technology

**“Ramanujan mock theta function and representations of****infinite-dimensional Lie superalgebra”**

**Abstract.** In his last letter to Hardy in 1920, Ramanujan listed 17 functions, which he called "mock theta functions" since they behave like theta functions but have no modular invariance properties of theta functions. Since then there have been substantial progress in understanding of mock theta functions.

About 10 years ago, Zwegers introduced non-holomorphic corrections, which made these functions modular. In the recent work with Wakimoto, we linked mock theta functions to representation theory of affine Lie superalgebras. This in turn sheds new light on the theory of mock theta functions.

On November 28, 2012 from 1-2 pm in room HH-3017, Dr. Yuanlin Li (Brock University) gave an AAC Colloquium talk "**Zero-divisor Graphs of Group Rings". **This talk is joint with Dr. Farid Aliniaeifard (Brock University).

The abstract for this talk is available here.

On February 1, 2012, Dr. Eduardo Martinez-Pedroza (Memorial University) gave an AAC Colloquium Talk "**Residual finiteness, subgroup separability and non-positively curved groups**"

In this talk the notions of residual finiteness and subgroup separability were discussed in connection with non-positively curved groups. Research on non-positively curved groups is motivated by the study of lattices in real rank one semi-simple Lie groups and manifold topology. Open questions, motivation, and some of my work in the area were discussed.

On November 16, 2011 Dr. **Sara Faridi** of Dalhousie University gave an AAC Colloqium talk "Combinatorics and Commutative Algebra"

That talk was about using graphs and hypergraphs to study questions in commutative algebra. Dr. Faridi discussed how problems in commutative algebra had led to the description of combinatorial structures that seemed to fit surprisingly well in the existed combinatorics literature. She also discussed open questions, and what the answers "should" look like.

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On January 12, 2011 Professor **Hugh Thomas** of University of New Brunswick - Fredericton gave a Distingushed Colloquium Talk entitled "Garside structures for braid groups".

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On October 6, 2010 Professor **Gerhard Pfister** from the University of Kaiserslautern, Germany gave the Distinguished Colloquium Talk entitled “SINGULAR and Applications”.

On April 1, 2010 Professor Donald S. Passman gave a Distingushed Colloquium Talk entitled ** Maximal Filtrations of Semisimple Rings and Lie Algebras**.

On March 26, 2010, Professor Mitja Mastnak of Saint Mary's University gave a Colloquium Talk titled ** Hopf Algebras in Combinatorics**.

On January 27, 2010, Professor Mikhail Kotchetov of Memorial University gave a Colloquium Talk titled ** Group gradings on simple Lie algebras**.

On May 29, 2009, an AAC Colloquium Talk **Group Algebras in Coding Theory** was given by Professor Cesar Polcino Milies of University of Sao Paulo. The abstract of the talk can be found ** here**.

On May 21, 2008, an AAC Colloquium Talk ** Hopf Algebras: from Hyperalgebras to Quantum Groups** was given by Professor Nicolas Andruskiewitsch of University of Cordoba, Argentina.

On November 2, 2007, an AAC Colloquium Talk ** Counting Factorizations of Permutations into Star Transpositions** was given by Professor John Irving of St. Marys University.

On August 20, 2007, an AAC Colloquium Talk ** Hurwitz groups: The classification problem** was given by Professor Alexandre Zalesski (right) of University of East Anglia, UK.

Our second mini course lecturer Professor Alexander Premet gave a talk ** Classification of the finite-dimensional simple Lie algebras of characteristic ** in the Distinguished Colloquium Series of the Department of Mathematics and Statistics of Memorial University of Newfoundland on May 23, 2007.

On February 22, 2007, an AAC Colloquium Talk ** Classical Invariant Theory Revisited** was given by Professor Roman Smirnov of Dalhousie University. He was visiting us from February 21 to February 23, 2007.

Our Atlantic Algebra colleague, Professor Margaret Beattie of Mount Allison University visited AAC from November 29 to December 2, 2006. On November 30 she gave a talk ** Coalgebras and Bilinear Forms** in our AAC Colloquium Series.

From October 27 to November 6, 2006, we had a visitor, Professor Vladislav Kharchenko of UNAM (National University of Mexico). He gave a Departmental Colloquium talk ** Lie algebras and their generalizations** on November 1, 2006.

On October 4, 2006 our first mini course speaker Amitai Regev gave a Distinguished Colloquium Talk under the title ** On asymptotic growth in PI algebras.**