Speaker: 

Anna Ma

Institution: 

UCI

Time: 

Wednesday, October 6, 2021 - 2:00pm to 3:00pm

Location: 

510R

Signed measurements of the form yi=sign(ai,x) for i[M] are ubiquitous in large-scale machine learning problems where the overarching task is to recover the unknown, unit norm signal xRd. Oftentimes, measurements can be queried adaptively, for example based on a current approximation of x, leading to only a subset of the M measurements being needed. Geometrically, these measurements emit a spherical hyperplane tessellation in Rd where one of the cells in the tessellation contains the unknown vector x. Motivated by this problem, in this talk we will present a geometric property related to spherical hyperplane tessellations in Rd. Under the assumption that ai are Gaussian random vectors, we will show that with high probability there exists a subset of the hyperplanes whose cardinality is on the order of dlog(d)log(M) such that the radius of the cell containing x induced by these hyperplanes is bounded above by, up to constants, dlog(d)log(M)/M. The work presented is joint work with Rayan Saab and Eric Lybrand.