3 papers
math.RA2026
Positivity preservers over finite fields II
Dominique Guillot, Himanshu Gupta, Prateek Kumar Vishwakarma +1
We say that a matrix over a finite field is positive definite if it is symmetric and each of its leading principal minors is a nonzero square in . In p…
math.CA2025
Entrywise transforms preserving matrix positivity and non-positivity
Dominique Guillot, Himanshu Gupta, Prateek Kumar Vishwakarma +1
We characterize real and complex functions which, when applied entrywise to square matrices, yield a positive definite matrix if and only if the original matrix is positive definit…
math.RA2024
Positivity preservers over finite fields
Dominique Guillot, Himanshu Gupta, Prateek Kumar Vishwakarma +1
We resolve an algebraic version of Schoenberg's celebrated theorem [Duke Math.J., 1942] characterizing entrywise matrix transforms that preserve positive definiteness. Compared to…