Seminars and Colloquia by Series

Some basics of Markov chain mixing times

Series
Lorentzian Polynomials Seminar
Time
Tuesday, October 22, 2019 - 14:50 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Prasad TetaliGeorgia Tech

This is quick tutorial on bounding the mixing time of a finite Markov chain in terms of functional inequalities defining the spectral gap and the entropy constant of a Markov chain. The lecture will include some examples, including bounding the mixing time of the random transposition shuffle and (time permitting) that of the basis-exchange walk on a balanced matroid.

This is intended as a review lecture before Nima Anari’s lectures (during Nov. 4-6) on applications of Lorentzian polynomials, including recent breakthrough analyses of the basis-exchange walk on an arbitrary matroid.

Deterministic algorithms for counting bases of a matroid

Series
Lorentzian Polynomials Seminar
Time
Tuesday, October 8, 2019 - 14:50 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Mohit SinghGeorgia Tech

We will discuss a deterministic, polynomial (in the rank) time approximation algorithm for counting the bases of a given matroid and for counting common bases between two matroids of the same rank. This talk follows the paper (https://arxiv.org/abs/1807.00929) of Nima Anari, Shayan Oveis Gharan, and Cynthia Vinzant.

Mason's Conjecture

Series
Lorentzian Polynomials Seminar
Time
Tuesday, October 1, 2019 - 14:50 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Trevor GunnGeorgia Tech

Using what we have studied in the Brändén-Huh paper, we will go over the proof of the ultra-log-concavity version of Mason's conjecture.

M-convexity and Lorentzian polynomials

Series
Lorentzian Polynomials Seminar
Time
Tuesday, September 17, 2019 - 14:50 for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Josephine YuGeorgia Tech

I will discuss a proof of the statement that the support of a Lorentzian polynomial is M-convex, based on sections 3-5 of the Brändén—Huh paper.