Combinatorics Seminar

SPEAKER:  Zilin Jiang  (MIT)

TITLE:  Sperical Tarski's Plank Problem

ABSTRACT: 

A zone of width ω on the unit sphere is defined as the set of points within spherical distance ω/2 of a given great circle.  Zones can be thought of as the spherical analogue of planks.  In this talk we show that the total width of any (finite) collection of zones covering the unit sphere is at least Π, answering a question of Fejes Toth from 1973.  This is joint work with Alexandr Polyanskii.