Yuchong Zhang

activity

20232025

collaborators

Showing math.COShow all

4 papers · 1 filter

math.CO2025

Multitriangulations on the half-cylinder

Saskia Solotko, Katherine Tung, Mengyuan Yang +1

We prove that the simplicial complex $Δ_{C_{n}, 2}$ is pure and a weak pseudomanifold of dimension $2 (n - 1)$ , where $Δ_{C_{n}, 2}$ is the simplicial complex associated…

math.CO2024

Postnikov--Stanley polynomials are Lorentzian

Serena An, Katherine Tung, Yuchong Zhang

Postnikov--Stanley polynomials $D_{u}^{w}$ are a generalization of skew dual Schubert polynomials to the setting of arbitrary Weyl groups. We prove that Postnikov--Stanley polynomials…

math.CO2024

Newton polytopes of dual Schubert polynomials

Serena An, Katherine Tung, Yuchong Zhang

The M-convexity of dual Schubert polynomials was first proven by Huh, Matherne, Mészáros, and St. Dizier in 2022. We give a full characterization of the supports of dual Schubert p…

math.CO2023

Characterizing positroid quotients of uniform matroids

Zhixing Chen, Yumou Fei, Jiyang Gao +2

We study two-step flag positroids $(P_{1}, P_{2})$ , where $P_{1}$ is a quotient of $P_{2}$ . We provide a complete characterization of all two-step flag positroids that contain a uniform…