Can small intersections determine global components?
seminario tenuto da
Giuliamaria Menara
Ottobre
20
Martedì
algebra e geometria
ore
11:15
presso Aula Vitali
In any fixed dimension, consider a finite collection of sets. The ordinary nerve records which intersections are nonempty, but forgets their connected components. Can we recover this missing information by looking at only a few sets at a time? I will discuss this question through a Helly-type theorem for sets with two convex components: under suitable local assumptions, the full intersection turns out to have exactly two convex components as well.