Ώρα: 11:00
Αίθουσα: Γ31
Ομιλητής: Filip Jevtić, Mathematical Institute of the Serbian Academy of Sciences and Arts
Τίτλος: Bier Spheres
Περίληψη: A Bier shpere is a simplicial complex defined as a deleted join of a simplicial complex and its Alexander dual. It doesn't have an a priori geometrical realization. Though combinatorially a shpere, in most cases it is not polytopal. When is it polytopal? When is it star-shaped? What is the volume of its geometrical realizations? What is its connection with threshold complexes? How is it connected to simple games? The results we'll show (partially) answer these questions and are a product of joint works with M. Timotijević and R.T. Živaljević.