Yuchong Zhang

activity

20232025

collaborators

5 papers

math.GT2025

Automorphisms of fine curve graphs of planar surfaces

Roberta Shapiro, Rohan Wadhwa, Arthur Wang +1

The fine curve graph of a surface is the graph whose vertices are simple closed essential curves in the surface and whose edges connect disjoint curves. In this paper, we prove tha…

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…