2 papers
math.CA2026
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.RA2025
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…