Finding the Sparsest Vectors in a Subspace: Theory, Algorithms, and Applications
Abstract
The problem of finding the sparsest vector (direction) in a low dimensional subspace can be considered as a homogeneous variant of the sparse recovery problem, which finds applications in robust subspace recovery, dictionary learning, sparse blind deconvolution, and many other problems in signal processing and machine learning. However, in contrast to the classical sparse recovery problem, the most natural formulation for finding the sparsest vector in a subspace is usually nonconvex. In this paper, we overview recent advances on global nonconvex optimization theory for solving this problem, ranging from geometric analysis of its optimization landscapes, to efficient optimization algorithms for solving the associated nonconvex optimization problem, to applications in machine intelligence, representation learning, and imaging sciences. Finally, we conclude this review by pointing out several interesting open problems for future research.
Cite
@article{arxiv.2001.06970,
title = {Finding the Sparsest Vectors in a Subspace: Theory, Algorithms, and Applications},
author = {Qing Qu and Zhihui Zhu and Xiao Li and Manolis C. Tsakiris and John Wright and René Vidal},
journal= {arXiv preprint arXiv:2001.06970},
year = {2020}
}
Comments
QQ and ZZ contributed equally to the work. Invited review paper for IEEE Signal Processing Magazine Special Issue on non-convex optimization for signal processing and machine learning. This article contains 26 pages with 11 figures