1 citations
2 papers
math.CA2026
The entrywise calculus and dimension-free positivity preservers, with an Appendix on sphere packings
Apoorva Khare
We present an overview of a classical theme in analysis and matrix positivity: the question of which functions preserve positive semidefiniteness when applied entrywise. In additio…
math.CA2026★ 1 cited
Negativity-preserving transforms of tuples of symmetric matrices
Alexander Belton, Dominique Guillot, Apoorva Khare +1
Compared to the entrywise transforms which preserve positive semidefiniteness, those leaving invariant the inertia of symmetric matrices reveal a surprising rigidity. We first obta…