# Events for 11/15/2021 from all calendars

## Geometry Seminar

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

**Location: ** zoom

**Speaker: **Tim Seynnaeve, U. Bern

**Title: ***Enumerative geometry for algebraic statistics and semidefinite programming*

**Abstract: **In statistics, the maximum likelihood degree of a statistical
model measures the algebraic complexity of maximum likelihood estimation. In
convex optimization, the algebraic degree of semidefinite programming
measures the algebraic complexity of solving the KKT equations. We
discovered that both of these numbers have an interpretation in terms of
classical problems in enumerative geometry. To phrase it in a more modern
language: they are intersection numbers on the variety of complete quadrics.
As an application, we prove a conjecture by Sturmfels and Uhler stating that
the maximum likelihood degree behaves polynomially. This illustrates both
how methods from algebraic geometry can be used to prove conjectures arising
in applications, but also how drawing inspiration from applications gives
rise to new geometric questions. This talk is based on joint projects with
Rodica Dinu, Laurent Manivel, Mateusz Michalek, Leonid Monin, and Martin
Vodicka.