*Apologies for multiple posting*
We are pleased to announce the next MaLGa Seminar Series - Analysis & Learning.
This event is part of the Ellis Genoa activities.
Speaker: Michaël Unser
Date: Thursday, April 21th, 2022
Time: 12:00 p.m.
Location: Room 705
Live streaming will be available at 705DIMA - YouTube
Title: The Radon transform, neural networks and splines
Abstract: Functional optimization is a powerful mechanism for deriving learning architectures, including kernel estimators and ReLU networks. In this talk, I first explain how this point of view can result in the specification of two complementary types of splines: the classical ones (RKHS) whose knots are tied to the data, and the adaptive ones (gTV) which are intrinsically sparse. I then show how the latter type of estimator can be transposed to neural nets by considering some special form of Radon-domain regularization. The corner stone of my formulation is a family of hyper-spherical Banach space over which the back-projection operator is invertible. This then yields a representer theorem for shallow ReLU networks that strengthens and clarifies results that have appeared in the literature.