Dimecres 24 d’abril se celebrarà una xerrada del Seminari Informal de Matemàtiques de Barcelona (SIMBa).

Conferenciant: Eva Philippe.
Universitat / Institut de recerca: Sorbonne Université i Universitat de Barcelona.

Data: Dimecres, 24 d’abril de 2024.
Hora: 13:00, pausa pel cafè; 13:20, xerrada.
Lloc: UB (FMI aula IA) and Zoom.
Idioma: Anglès.

Títol: Regular subdivisions and triangulations.

Resum: Subdivisions and triangulations of point configurations in $\mathbb{R}^d$ are a central topic of polyhedral combinatorics and among them regular subdivisions form a particular family which enjoys special geometric properties.
A subdivision is regular if it can be obtained by taking the lower faces of a lifting of its vertices in one dimension higher. This lifting process was central to improve the best known lower bound on the number of combinatorial types of polytopes (joint work with Arnau Padrol and Francisco Santos). Moreover, it happens that among the set of all subdivisions of a fixed point configuration, the regular ones have a particular topological structure. Indeed, they are in correspondence with the faces of a polytope called the secondary polytope.