Peer-reviewedCC BY-NC-NDCommunications of the American Mathematical Society
Comparison theorems for the minimum eigenvalue of a random positive-semidefinite matrix
Abstract
This paper establishes a new comparison principle for the minimum eigenvalue of a sum of independent random positive-semidefinite matrices. The principle states that the minimum eigenvalue of the matrix sum is controlled by the minimum eigenvalue of a Gaussian random matrix whose statistics are determined by the summands. This methodology is powerful because of the vast arsenal of tools for treating Gaussian random matrices. As applications, the paper presents short, conceptual proofs of some old and new results in high-dimensional statistics. It also settles a long-standing open question in computational linear algebra about the injectivity properties of very sparse random matrices.
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BibTeX
@article{tropp2026comparison,
title = {{Comparison theorems for the minimum eigenvalue of a random positive-semidefinite matrix}},
author = {Joel A. Tropp},
journal = {Communications of the American Mathematical Society},
year = {2026},
month = jul,
doi = {10.1090/cams/72},
url = {https://doi.org/10.1090/cams/72},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Comparison theorems for the minimum eigenvalue of a random positive-semidefinite matrix
AU - Joel A. Tropp
PY - 2026
DA - 2026/07/07
JO - Communications of the American Mathematical Society
DO - 10.1090/cams/72
UR - https://doi.org/10.1090/cams/72
AB - This paper establishes a new comparison principle for the minimum eigenvalue of a sum of independent random positive-semidefinite matrices. The principle states that the minimum eigenvalue of the matrix sum is controlled by the minimum eigenvalue of a Gaussian random matrix whose statistics are determined by the summands. This methodology is powerful because of the vast arsenal of tools for treating Gaussian random matrices. As applications, the paper presents short, conceptual proofs of some old and new results in high-dimensional statistics. It also settles a long-standing open question in computational linear algebra about the injectivity properties of very sparse random matrices.
SN - 2692-3688
ER -