Finite point configurations and multilinear Radon transforms

Seminar: 
Applied Mathematics
Event time: 
Tuesday, December 1, 2015 - 11:15am to 12:15pm
Location: 
AKW 200
Speaker: 
Eyvindur Palsson
Speaker affiliation: 
Williams College
Event description: 

As big data sets have become more common, there has been significant interest in finding and understanding patterns in them. One example of a simple pattern is the distance between data points, which can be thought of as a 2-point configuration. 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, explore that simple pattern. 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 present recent Falconer type theorems, established by myself and my collaborators, for a wide class of finite point configurations in any dimension. The techniques we used come from analysis and geometric measure theory, and the key step was to obtain bounds on multilinear analogues of generalized Radon transforms. Further study of these multilinear operators lead to a variety of interesting applications, such as multilinear analogs of Stein’s spherical maximal theorem.