Algebraic Combinatorics Seminar - Federico Castillo

Thursday, March 3, 2022 1:00 pm - 1:00 pm EST (GMT -05:00)

Title: Lineup polytopes and exclusion principles

Speaker: Federico Castillo
Affiliation: Universidad Catolica de Chile
Zoom link: Contact Logan Crew

Abstract:

The set of all possible spectra of 1-reduced density operators for systems of N particles on a d-dimensional Hilbert space is a polytope called hypersimplex and this is related to Pauli's exclusion principle. If the spectrum of the original density operators is fixed, the set of spectra (ordered decreasingly) of 1-reduced density operators is also a polytope. A theoretical description of this polytope using inequalities was provided by Klyachko in the early 2000's.

Adapting and enhancing tools from discrete geometry and combinatorics (symmetric polytopes, sweep polytopes, and the Gale order), we obtained such necessary inequalities explicitly, that are also valid for arbitrarily large N and d.

This approach leads to a new class of polytopes called lineup polytopes.

This is joint work with physicists Jean Philippe Labbe, Julia Liebert, Eva Philippe, Arnau Padrol, and Christian Schilling.