Colloquia

The Pure Math colloquium is held roughly every other week during the fall and winter terms. The talks are at 4:00 pm on Mondays in the Math and Computer Building (MC) 5501, and are preceded by refreshments with the speaker at 3:30 pm in MC 5403.

Upcoming colloquia


Colloquium
Monday, October 28, 2019
4:00 pm - MC 5501
Speaker: Alexander Yong, University of Illinois at Urbana-Champaign
Title: Complexity, combinatorial positivity, and Newton polytopes
Abstract: The Nonvanishing Problem asks if a coefficient of a polynomial is nonzero. Many families of polynomials in algebraic combinatorics admit combinatorial counting rules and simultaneously enjoy having saturated Newton polytopes (SNP). Thereby, in amenable cases, Nonvanishing is in the complexity class of problems with “good characterizations”. This suggests a new algebraic combinatorics viewpoint on complexity theory. 

This talk discusses the case of Schubert polynomials. These form a basis of all polynomials and appear in the study of cohomology rings of flag manifolds. We  give a tableau criterion for Nonvanishing, from which we deduce the first polynomial time algorithm. These results are obtained from new characterizations of the Schubitope, a generalization of the permutahedron defined for any subset of the n x n grid, together with a theorem of A. Fink, K. Meszaros and A. St. Dizier, which proved a conjecture of C. Monical, N. Tokcan and the speaker. 

This is joint with Anshul Adve (U. California, Los Angeles, USA) and Colleen Robichaux (U. Illinois at Urbana-Champaign, USA).


Colloquium
Monday, November 4, 2019
4:00 pm - MC 5501
Speaker: Henry Yuen, University of Toronto
Title: TBA
Abstract: TBA


Colloquium
Monday, November 25, 2019
4:00 pm - MC 5501
Speaker: James Freitag, University of Illinois at Chicago
Title: TBA
Abstract: TBA


Colloquium
Monday, December 2, 2019
4:00 pm - MC 5501
Speaker: Messoud Efendiyev, Helmholtz Zentrum Munich
Title: TBA
Abstract: TBA


Colloquium
Monday, January 13, 2020
4:00 pm - MC 5501
Speaker: Dimitris Koukoulopoulos, Université de Montréal
Title: TBA
Abstract: TBA


Colloquium
Monday, January 20, 2020
4:00 pm - MC 5501
Speaker: Igor Shparlinski, University of New South Wales 
Title: TBA
Abstract: TBA


Here is an archive of past colloquia.