PreprintarXiv licencearXiv
Duality for matrix space questions
Abstract
We present a new proof of a classical theorem of Dieudonné: if a linear space of n× n matrices consists entirely of singular matrices, then its dimension is at most n2−n. Our proof is based on a surprising ``duality'' argument: we prove this universal upper bound by exhibiting a single matrix space that serves as a lower bound for a related problem. Interestingly, this approach only works for certain fields, but we use model-theoretic arguments to obtain the same result for all fields. We hope that this approach can be generalized to provide new duality-based proofs of other classical theorems on matrix spaces, and give some preliminary results in this direction.
Related
- A complete curve of genus 5 in the moduli space of curves of genus 3 and related questions
- Matrix-weighted Z-spaces and tent spaces:characterizations, duality and interpolation
- A Duality Reformulation of the Companion-Matrix Lyapunov Problem
- Strong Duality Thresholds and Minimum Curvature for the Nearest Rectangular Symplectic Matrix Problem
- Hermitian Clifford Analysis on Euclidean Domains with Smooth and Fractal Boundaries: A Survey of Matrix Cauchy and Hilbert Transforms, Boundary Value Problems, Helmholtz-Type Dirac Operators and Duality
BibTeX
@misc{wigderson2026duality,
title = {{Duality for matrix space questions}},
author = {Yuval Wigderson},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.29177},
eprint = {2609.29177},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.29177},
}
RIS
TY - UNPB
TI - Duality for matrix space questions
AU - Yuval Wigderson
PY - 2026
DA - 2026/09/24
PB - arXiv
DO - 10.48550/arxiv.2609.29177
UR - https://arxiv.org/abs/2609.29177
AB - We present a new proof of a classical theorem of Dieudonné: if a linear space of n× n matrices consists entirely of singular matrices, then its dimension is at most n^2−n. Our proof is based on a surprising ``duality'' argument: we prove this universal upper bound by exhibiting a single matrix space that serves as a lower bound for a related problem. Interestingly, this approach only works for certain fields, but we use model-theoretic arguments to obtain the same result for all fields. We hope that this approach can be generalized to provide new duality-based proofs of other classical theorems on matrix spaces, and give some preliminary results in this direction.
ER -