2 papers
math.CO2025
On universal quadratic inequalities for minors of TNN matrices
Vladimir I. Danilov, Alexander V. Karzanov, Gleb A. Koshevoy
For positive integers , we give a combinatorial characterization for the set of quadratic inequalities on minors that are valid for all totally nonnegative matri…
math.CO2024
On Manin-Schechtman orders related to directed graphs
Vladimir I. Danilov, Alexander V. Karzanov, Gleb A. Koshevoy
As a generalization of weak Bruhat orders on permutations, in 1989 Manin and Schechtman introduced the notion of a higher Bruhat order on the -element subsets of a set $[n]=\{1,…