Bi-annual Algebraic and Tropical Meetings of
Brown and YaLE

Fall 2016 @ Brown
September 20, 2016

The BATMOBYLE is a vehicle for bringing together the algebraic and tropical geometry groups of Brown and Yale for a biannual day of talks alternating between the two universities.

Bernd Sturmfels

Bernd Sturmfels

(UC Berkeley)
Nearest Points on Toric Varieties

Abstract: This talk concerns the following optimization problem: given a data point, find its best approximation in a model that is parametrized by monomials. This algebraic complexity of this problem is given by the Euclidean distance degree of a projective toric variety. We present a formula for this degree. It extends the formula of Matsui and Takeuchi for the degree of the A-discriminant in terms of Euler obstructions. The motivation for this work is the development of our optimization problem. A key ingredient is the study of characteristic classes such as the Chern-Mather class. This is joint work with Martin Helmer.

11:00 - 12:00 Tropical curves of genus 2
Ralph Morrison (Williams)
Room: Kassar 205*
12:00 - 02:00 Lunch
02:00 - 03:00 Derived category of moduli spaces of pointed stable rational curves
Ana-Maria Castravet (Northeastern)
Room: Kassar 205*
03:00 - 04:00 Tea Common room
04:00 - 05:00 Plenary Talk: Nearest Points on Toric Varieties
Bernd Sturmfels (UC Berkeley)
Room: Kassar 205*

*All talks will be held in Kassar 205. Kassar House is located on the corners of George Street and Thayer Street. Please use the Thayer street entrance-- the math department is on the left side of the annex.

Brown Organizers:
Dan Abramovich (Brown), Kenny Ascher (Brown), Melody Chan (Brown), Brendan Hassett (Brown), and Nathan Pflueger (Brown).

Yale Organizers:
Asher Auel (Yale), Angie Cueto (Ohio State), José González (UC Riverside), Kalina Mincheva (Yale), and Sam Payne (Yale).

Previous BATMOBYLEs: Fall 2014, Spring 2015, Fall 2015, Spring 2016
Mirrored site at Brown