Recovering Simultaneously Structured Data via Non-Convex Iteratively Reweighted Least Squares

Abstract

We propose a new algorithm for the problem of recovering data that adheres to multiple, heterogeneous low-dimensional structures from linear observations. Focusing on data matrices that are simultaneously row-sparse and low-rank, we propose and analyze an iteratively reweighted least squares (IRLS) algorithm that is able to leverage both structures. In particular, it optimizes a combination of non-convex surrogates for row-sparsity and rank, a balancing of which is built into the algorithm. We prove locally quadratic convergence of the iterates to a simultaneously structured data matrix in a regime of minimal sample complexity (up to constants and a logarithmic factor), which is known to be impossible for a combination of convex surrogates. In experiments, we show that the IRLS method exhibits favorable empirical convergence, identifying simultaneously row-sparse and low-rank matrices from fewer measurements than state-of-the-art methods.

Publication
In Advances in Neural Information Processing Systems 36 (NeurIPS 2023)
Christian Kümmerle
Christian Kümmerle
Assistant Professor
School of Data, Mathematical, and Statistical Sciences
Department of Computer Science
Institute for Artificial Intelligence

I am passionate about the potential of AI and operations research for Lightning network operations and about efficiency gains within AI models that can be unlocked by combining smoothing, parsimony, structured optimization.