Abstract for the talk on 19.03.2020 (17:40 h)

Nonlinear Algebra Seminar Online (NASO)

Jean-Philippe Labbé (Freie Universität Berlin)
Convex geometry of subword complexes
See the video of this talk.

Steinitz’s problem asks whether a triangulated sphere is realizable geometrically as the boundary of a convex polytope. The determination of the polytopality of subword complexes is a resisting instance of Steinitz’s problem. Indeed, since their creation more than 15 years ago, subword complexes built up a wide portfolio of relations and applications to many other areas of research (Schubert varieties, cluster algebras, associahedra, tropical Grassmannians, to name a few) and a lot of efforts has been put into realizing them as polytopes, with little success. In this talk, I will present some reasons why this problem resisted so far, and present a glimpse of a novel approach to study the problem grouping together Schur functions, combinatorics of words, and oriented matroids.

 

27.03.2020, 18:08