activity
20192026
most citedElliptic PDE learning is provably data-efficient

17 citations · 23 across the 14 of their papers we have counts for

collaborators

16 papers

math.NA2026

Hutch#: Optimal non-adaptive Frobenius norm estimation

Tyler Chen, Diana Halikias, Christopher Musco +1

The Girard--Hutchinson estimator provides an extremely simple randomized estimate of the Frobenius norm of a matrix that can only be accessed implicitly via matrix-vector produ…

cs.LG2026

Subzero matrix completion for sparse data analysis: large-scale learning of latent low-rank structure

Lawrence K. Saul, Ningyuan Huang, Dennis Bollweg +2

We investigate when a sparse nonnegative matrix can be recovered from a real-valued matrix of much lower rank by zeroing out its negative elements. The potential for such decomposi…

math.NA2026

A recursive butterfly factorization with optimality guarantees

David Persson, Paul G. Beckman, Tyler Chen +2

We formalize a recursive format for representing a butterfly matrix. This new format naturally leads to a simple recursive algorithm for computing a quasi-optimal butterfly approxi…

math.NA2026

A zero-one law for one-shot system identification

Nicolas Boullé, Diana Halikias, Samuel E. Otto +1

Can a model be identified from one experiment? We study analytic systems that are linearly parameterized by a combination of prescribed dictionary terms, such as partial differenti…

math.NA2026

Transpose-free linear algebra

Diana Halikias, Michiel E. Hochstenbach, Alex Townsend

We study the limitations of matrix-free algorithms that access a matrix only through forward matrix-vector products (matvecs) , without access to the transpose $A…

math.NA2026

Attention Mechanisms Through the Lens of Numerical Methods: Approximation Methods and Alternative Formulations

Michel Fabrice Serret, Alice Cortinovis, Yijun Dong +10

The attention mechanism is the computational core of modern Transformer architectures, but its quadratic complexity in the input sequence length is the bottleneck for large-scale i…

math.NA2026

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

Noah Amsel, Yves Baumann, Paul Beckman +33

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.NA2025

Quasi-optimal hierarchically semi-separable matrix approximation

Noah Amsel, Tyler Chen, Feyza Duman Keles +4

We present a randomized algorithm for producing a quasi-optimal hierarchically semi-separable (HSS) approximation to an matrix using only matrix-vector products wit…

cs.DS2024

Near-optimal hierarchical matrix approximation from matrix-vector products

Tyler Chen, Feyza Duman Keles, Diana Halikias +3

We describe a randomized algorithm for producing a near-optimal hierarchical off-diagonal low-rank (HODLR) approximation to an matrix , accessible only thou…

cs.DS2024

Fixed-sparsity matrix approximation from matrix-vector products

Noah Amsel, Tyler Chen, Feyza Duman Keles +3

We study the problem of approximating a matrix with a matrix that has a fixed sparsity pattern (e.g., diagonal, banded, etc.), when is accessed only by ma…

math.NA2024

Operator learning without the adjoint

Nicolas Boullé, Diana Halikias, Samuel E. Otto +1

There is a mystery at the heart of operator learning: how can one recover a non-self-adjoint operator from data without probing the adjoint? Current practical approaches suggest th…

cs.LG2023★ 17 cited

Elliptic PDE learning is provably data-efficient

Nicolas Boullé, Diana Halikias, Alex Townsend

PDE learning is an emerging field that combines physics and machine learning to recover unknown physical systems from experimental data. While deep learning models traditionally re…

math.NA2022★ 1 cited

Structured matrix recovery from matrix-vector products

Diana Halikias, Alex Townsend

Can one recover a matrix efficiently from only matrix-vector products? If so, how many are needed? This paper describes algorithms to recover matrices with known structures, such a…

cs.LG2021★ 5 cited

Arbitrary-Depth Universal Approximation Theorems for Operator Neural Networks

Annan Yu, Chloé Becquey, Diana Halikias +2

The standard Universal Approximation Theorem for operator neural networks (NNs) holds for arbitrary width and bounded depth. Here, we prove that operator NNs of bounded width and a…

math.MG2019

Discrete variants of Brunn-Minkowski type inequalities

Diana Halikias, Bo'az Klartag, Boaz A. Slomka

We present an alternative, short proof of a recent discrete version of the Brunn-Minkowski inequality due to Lehec and the second named author. Our proof also yields the four funct…

math.SP2019

A Cheeger inequality for graphs based on a reflection principle

Edward Gelernt, Diana Halikias, Charles Kenney +1

Given a graph with a designated set of boundary vertices, we define a new notion of a Neumann Laplace operator on a graph using a reflection principle. We show that the first eigen…