Geometric averaging operators and points configurations

Analysis Seminar
Wednesday, February 26, 2020 - 1:55pm for 1 hour (actually 50 minutes)
Skiles 005
Eyvindur Ari Palsson – Virginia Tech –
Michael Lacey

Two classic questions -- the Erdos distinct distance problem, which asks about the least number of distinct distances determined by N points in the plane, and its continuous analog, the Falconer distance problem -- both focus on the distance, which is a simple two point configuration. When studying the Falconer distance problem, a geometric averaging operator, namely the spherical averaging operator, arises naturally. Questions similar to the Erdos distinct distance problem and the Falconer distance problem can also be posed for more complicated patterns such as triangles, which can be viewed as 3-point configurations. In this talk I will give a brief introduction to the motivating point configuration questions and then report on some novel geometric averaging operators and their mapping properties.