## Thursday, November 19, 2020

### Manjil Saikia (Cardiff University) November 26, 2020: 3:55 PM to 5:00 PM (IST)

The next talk is by Manjil Saikia of Cardiff University.  The remaining two talks of the year will be on December 10 and December 17.

We will begin the new year with a special public lecture by Wadim Zudilin. More details as we come nearer 2021.

Talk announcement

Title: Refined enumeration of symmetry classes of Alternating Sign Matrices

Speaker: Manjil P. Saikia  (Cardiff University)

When: November 26, 2020 - 3:55 PM - 5:00 PM (IST)

Where: Google Meet; Please write to sfandnt@gmail.com if you want a link.

Tea or Coffee: Please bring your own.

ABSTRACT:

The sequence $1,1,2,7,42,429, \ldots$ counts several combinatorial objects, some of which I will describe in this talk. The major focus would be one of these objects, alternating sign matrices (ASMs). ASMs are square matrices with entries in the set {0,1,-1}, where non-zero entries alternate in sign along rows and columns, with all row and column sums being 1. I will discuss some questions that are central to the theme of ASMs, mainly dealing with their enumeration. In particular we shall prove some conjectures of Fischer, Robbins, Duchon and Stroganov. This talk is based on joint work with Ilse Fischer and some ongoing work.