On the Koldobsky's slicing conjecture for measures

Analysis Seminar
Wednesday, September 12, 2018 - 1:55pm for 1 hour (actually 50 minutes)
Skiles 005
Galyna Livshyts – Georgia Institute of Technology – glivshyts6@math.gatech.eduhttp://people.math.gatech.edu/~glivshyts6/
Galyna Livshyts
Koldobsky showed that for an arbitrary measure on R^n, the measure of the largest section of a symmetric convex body can be estimated from below by 1/sqrt{n}, in with the appropriate scaling. He conjectured that a much better result must hold, however it was recemtly shown by Koldobsky and Klartag that 1/sqrt{n} is best possible, up to a logarithmic error. In this talk we will discuss how to remove the said logarithmic error and obtain the sharp estimate from below for Koldobsky's slicing problem. The method shall be based on a "random rounding" method of discretizing the unit sphere. Further, this method may be effectively applied to estimating the smallest singular value of random matrices under minimal assumptions; a brief outline shall be mentioned (but most of it shall be saved for another talk). This is a joint work with Bo'az Klartag.