3 papers
math.FA2026
Entrywise preservers of sign regularity
Projesh Nath Choudhury, Shivangi Yadav
Entrywise functions preserving positivity and related notions have a rich history, beginning with the seminal works of Schur, Pólya-SzegÅ, Schoenberg, and Rudin. Following their…
math.FA2025
Sign regularity preserving linear operators
Projesh Nath Choudhury, Shivangi Yadav
A matrix is strictly sign regular/SSR (or sign regular/SR) if for each , all (non-zero) minors of have the…
math.RA2025
Constructing strictly sign regular matrices of all sizes and sign patterns
Projesh Nath Choudhury, Shivangi Yadav
The class of strictly sign regular (SSR) matrices has been extensively studied by many authors over the past century, notably by Schoenberg, Motzkin, Gantmacher, and Krein. A class…