# Mathematics Colloquia and Seminars

### Characterizing quotients of positroids

Algebra & Discrete Mathematics

 Speaker: Anastasia Chavez, UC Davis Related Webpage: https://www.math.ucdavis.edu/people/general-profile?fac_id=anachavez Location: 1147 MSB Start time: Mon, Oct 28 2019, 2:10PM

We characterize quotients of specific families of positroids. Positroids
are a special class of representable matroids introduced by Postnikov in
the study of the nonnegative part of the Grassmannian. Postnikov defined
several combinatorial objects that index positroids. In this talk, we
make use of two of these objects to combinatorially characterize when
certain positroids are quotients. Furthermore, we conjecture a general
rule for quotients among arbitrary positroids on the same ground set.
This is joint work with Carolina Benedetti and Daniel Tamayo.

Please note the unusual time for the seminar this week!