Felix Krahmer


TU Munich


Tuesday, December 3, 2019 - 11:00am to 11:50am



RH 340N


We present recent results on the geometry of centrally-symmetric random polytopes generated by N independent copies of a random vector X. We show that under minimal assumptions on X, for N>Cn, and with high probability, the polytope contains a deterministic set that is naturally associated with the random vector - namely, the polar of a certain floating body. This solves the long-standing question on whether such a random polytope contains a canonical body. Moreover, by identifying the floating bodies associated with various random vectors we recover the estimates that have been obtained previously, and thanks to the minimal assumptions on X we derive estimates in cases that had been out of reach, involving random polytopes generated by heavy-tailed random vectors (e.g., when X is q-stable or when X has an unconditional structure). Finally, the structural results are used for the study of a fundamental question in compressive sensing - noise blind sparse recovery. This is joint work with the speaker's PhD student Christian Kümmerle (now at Johns Hopkins University) as well as Olivier Guédon (University of Paris-Est Marne La Vallée), Shahar Mendelson (Sorbonne University Paris), and Holger Rauhut (RWTH Aachen).