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.