The Applied Algebra Seminar
A Monday afternoon research seminar

About the seminar (click here to see more)


The seminar is currently organized by Lucas Gagnon and Nantel Bergeron.

Schedule

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

Fall 2024

Date Speaker Title (click titles for abstract)
16 Dec. 2024 Seeking Speaker!
TBA
9 Dec. 2024 Seeking Speaker!
2 Dec. 2024 Seeking Speaker!
TBA
25 Nov. 2024
Ravali Nookala
TBA
18 Nov. 2024 Karen Yeats
U. Waterloo
TBA
11 Nov. 2024
Seeking Speaker!
TBA
4 Nov. 2024 Seeking Speaker!
TBA
28 Oct. 2024
Aaron Lauve
Loyola Chicago
TBA
21 Oct. 2024 Lucas Gagnon
York
TBA
Reading Week
7 Oct. 2024 Jerónimo Valencia
U. Waterloo
A combinatorial proof of an identity involving Eulerian numbers
In 2009, Brenti and Welker studied the Veronese construction for formal power series which was motivated by the corresponding construction for graded algebras. As a corollary of their algebraic computations, they discovered an identity for the coefficients of the Eulerian polynomials. The authors asked for a combinatorial proof of this identity given that all of its ingredients are enumerative in nature. In this talk I will present one such combinatorial proof.
30 Sept. 2024 Nantel Bergeron
York
A quantum Murnaghan--Nakayama rule for the flag manifold
Based on joint work with Benedetti, Colmenarejo, Saliola, and Sottile (arxiv:2406.053311). We give a rule for the multiplication of a Schubert class by a tautological class in the (small) quantum cohomology ring of the flag manifold. As an intermediate step, we establish a formula for the multiplication of a Schubert class by a quantum Schur polynomial indexed by a hook partition. This entails a detailed analysis of chains and intervals in the quantum Bruhat order. This analysis allows us to use results of Leung--Li and of Postnikov to reduce quantum products by hook Schur polynomials to the (known) classical product.
23 Sept. 2024 Hugh Thomas
UQAM
Cyclic actions on noncrossing and nonnesting partitions
Noncrossing partitions and nonnesting partitions are both counted by Catalan numbers. Noncrossing partitions on [n] admit a natural cyclic action of order 2n, induced by the Kreweras complement. Nonnesting partitions admit a natural toggle-based action; in fact, they admit one such action for each choice of Coxeter element of the symmetric group. We prove that the latter actions all have order 2n by constructing a family of bijections between noncrossing and nonnesting partitions, equivariant with respect to the cyclic actions on either side. This talk is based on arXiv:2212.14831, joint with Benjamin Dequêne, Gabriel Frieden, Alessandro Iraci, Florian Schreier-Aigner, and Nathan Williams. Our results were presented at FPSAC in July; our extended abstract (and Nathan's slides) are available from the FPSAC website.

Archives

Below you will find links to the seminar webpages for previous years.
Year 2023-24 Year 2022-23 Year 2020-21 Year 2019-20 Year 2018-19
Year 2017-18 Year 2016-17 Year 2015-16 Year 2014-15 Year 2013-14
Year 2012-13 Year 2011-12 Year 2010-11 Year 2009-10 Year 2008-09
Fall 2007 Winter 2006 Fall 2005 Winter 2005 Fall 2004
Winter 2004 Fall 2003 Winter 2003 Fall 2002 Winter 2002
Fall 2001 Winter 2001 Fall 2000 Winter 2000 Fall 1999
Winter 1999 Fall 1998 Winter 1998 Fall 1997