collaborators

7 papers

math.NA2026

Sharp analysis of sketched least squares and randomized low-rank approximation

Ethan N. Epperly, Robert J. Webber

Two widely used randomized algorithms are the sketch-and-solve method for least-squares regression and the randomized SVD for low-rank approximation. These algorithms apply a rando…

math.NA2026

Linear Systems and Eigenvalue Problems: Open Questions from a Simons Workshop

Noah Amsel, Yves Baumann, Paul Beckman +36

This document presents a series of open questions arising in matrix computations, i.e., the numerical solution of linear algebra problems. It is a result of working groups at the w…

math.NA2026

Everything is Vecchia: Unifying low-rank and sparse inverse Cholesky approximations

Eagan Kaminetz, Robert J. Webber

The partial pivoted Cholesky approximation accurately represents matrices that are close to being low-rank. Meanwhile, the Vecchia approximation accurately represents matrices with…

math.NA2026

Keep the beat going: Automatic drum transcription with momentum

Alisha L. Foster, Robert J. Webber

How can we process a piece of recorded music to detect and visualize the onset of each instrument? A simple, interpretable approach is based on partially fixed nonnegative matrix f…

stat.ME2025

Variational Markov chain mixtures with automatic component selection

Christopher E. Miles, Robert J. Webber

Markov state modeling has gained popularity in various scientific fields since it reduces complex time-series data sets into transitions between a few states. Yet common Markov sta…

math.NA2025

Randomized Kaczmarz with tail averaging

Ethan N. Epperly, Gil Goldshlager, Robert J. Webber

The randomized Kaczmarz (RK) method is a well-known approach for solving linear least-squares problems with a large number of rows. RK accesses and processes just one row at a time…