Wei Xie

collaborators

3 papers

math.CO2026

Minor-Order Exponent Profiles of Oscillatory Matrices

Wei Xie

For an $n \times n$ oscillatory matrix $A$ , let $e_{k} (A)$ be the least positive integer $m$ for which every minor of order $k$ of $A^{m}$ is positive. We determine the profile $(e_1(A)…

math.RA2026

Entrywise Positivity Preservers on Green Matrices

Wei Xie

We classify the entrywise functions that preserve positive semidefiniteness on discrete Green matrices $G(p,q)=(p_{\min(i,j)}q_{\max(i,j)})$ with positive parameters, without req…

math.FA2026

Entrywise Loewner Preservers on Min and Max Matrix Cones

Wei Xie

Let \[ A_{\min}(x)=\bigl(x_{\min(i,j)}\bigr)_{i,j=1}^n, \qquad A_{\max}(x)=\bigl(x_{\max(i,j)}\bigr)_{i,j=1}^n \] be the Min and Max matrices generated by a real sequence \(x=(x_1,…