# Events for 11/14/2019 from all calendars

## Several Complex Variables Seminar

**Time:** 2:00PM - 3:00PM

**Location:** BLOC 220

**Speaker:** Debraj Chakrabarti, Central Michigan University

**Title:** *An Alexander-Pontrjagin type duality in the L ^{2} theory of the ∂-operator*

**Abstract:** Hörmander's L^{2} estimates on the ∂-equation on bounded pseudoconvex domains are a cornerstone of modern complex analysis. From the very beginning, attempts have been made (by Folland-Kohn, Shaw, Hörmander and others) to extend these L^{2} methods to appropriate classes of nonpseudoconvex domains. In this talk, we discuss an approach to the ∂-problem on an annulus between two weakly pseudoconvex domains which is inspired by Alexander-Pontrjagin duality in topology. This is ongoing joint work with Phil Harrington of Arkansas.

## Student/Postdoc Working Geometry Seminar

**Time:** 3:00PM - 4:00PM

**Location:** BLOC 628

**Speaker:** CJ Bott, TAMU

**Title:** *Mukai 11-14*

## Geometry Seminar

**Time:** 4:00PM - 5:00PM

**Location:** BLOC 628

**Speaker:** M. Michalek, MPI Leipzig

**Title:** *C^*-actions, ML-degree and various Grassmannians*

**Abstract:** Central questions in many branches of mathematics are related to understanding the cohomology class of a graph of a Cremona transformation. One case is statistics, where the Maximum Likelihood degree of Gaussian models can be expressed exactly in this terms. I will report on work in progress with Wisniewski, where we upgrade the relevant Cremona transformation to a C^* action on a blow up of a homogeneous variety. This leads to a new computational approach towards the ML degree.