The Applied Algebra Seminar

A
Monday afternoon research seminar

The seminar is currently organized by John Machacek and Nantel Bergeron.

During 2018-19, the seminar takes place from 15:00-16:00 in Ross Building room N638. If you come by public transportation, there is a York University subway station on the TTC Line 1 Yonge-Univerity route. If you come by car, you can find the available parking lots here.

The seminar has been running since 1997. The topics of talks have typically been any mixture of algebra with any other field: combinatorics, geometry, topology, physics, etc. Further down this page you will find links to the seminar webpages for previous years. The audience usually consists of 6–12 people, including several graduate students and post-docs. For this reason, speakers are encouraged to devote a portion of their talk to the suggestion of open problems and the directions for research in their area. If you are interested in speaking at the seminar, contact John Machacek or Nantel Bergeron.You may also be interested in the Algebraic Combinatorics Seminar at the Fields Institute.

Dates are listed in reverse-chronological order. Unless otherwise indicated, all talks will take place on Monday from 15:00-16:00 in N638 Ross Building (York University).

Date Speaker Title (click titles for abstract) 3 Dec. 2018 Gabriel Frieden

(CRM-ISM)26 Nov. 2018

Justin Troyka

(York University)19 Nov. 2018 Tianyuan Xu

(Queen's University)12 Nov. 2018

Pauline Hubert

(UQAM)5 Nov. 2018 Aram Dermenjian

(UQAM)29 Oct. 2018

Robin Sulzgruber

(York University)22 Oct. 2018 Hugo Mlodecki

(Paris-Sud)Auto-duality of WQSym, the Hopf algebra on packed words A Hopf algebra is a formalism that makes it possible to study algorithms on combinatorial object assembling and disassembling. Among these objects, we find the permutations where each number between 1 and n appears one and only once, or the packed words where each number between 1 and m appears at least once. We will study different ways of assembling and disassembling permutations and the relationships of duality and simple auto-duality that these operations verify. We will then try to generalize these relations to the packed words along a more complex path.15 Oct. 2018 John Machacek

(York University)Locally acyclic cluster algebras and their quivers We will dicuss locally acyclic cluster algebras and techniques for showing a cluster algebra is locally acyclic. We will also explore to realationship between the existence of a reddening sequence and equality of a cluster algebra and its upper cluster algebra.8 Oct. 2018 ThanksgivingNo Seminar1 Oct. 2018 Kelvin Chan

(York University)Induction Relations in the Symmetric Groups and Jucys-Murphy Elements Transitive factorizations faithfully encode many interesting objects. The well-known ones include ramified coverings of the sphere and hypermaps. Enumeration of specific classes of such objects have been known for quite some time now. Hurwitz numbers, monotone Hurwitz numbers and hypermaps numbers were discovered using different techniques. Recently, Carrell and Goulden found a unified algebraic approach to count these objects in genus 0. Jucys-Murphy elements and centrality play important roles in establishing induction relations. Such a method is interesting in its own right. Its corresponding combinatorial decomposition is however intriguingly mysterious. Towards a understanding of direct combinatorial analysis of multiplication of arbitrary permutations, we consider methods, especially operators on symmetric functions, and related problems in symmetric groups.24 Sep. 2018 LaCIM celebrationNo Seminar

Below you will find links to the seminar webpages for previous years.