collaborators

6 papers

math.CO2026

Two families of Hermite normal form simplices

Feihu Liu, Jinlong Tang, Sihao Tao +1

We study Ehrhart coefficients, the integer decomposition property, and unimodular triangulations for two families of Hermite normal form simplices considered by Bruckamp, Caicedo,…

math.CO2026

Ehrhart Theory of the Join of Two Lattice Polytopes

Feihu Liu, Sihao Tao, Guoce Xin

Inspired by research on the Cartesian product of two lattice polytopes, this paper investigates the Ehrhart theory of the join of two lattice polytopes. This is also a well-known o…

math.CO2026

Explicit Construction of Polytopes whose Ehrhart Polynomials Realize any Given Sign Pattern

Feihu Liu, Sihao Tao, Guoce Xin

In Ehrhart theory, the well-known sign pattern problem asks: given a positive integer and integers , does there exist a -dimensiona…

math.CO2026

Unimodular Equivalence of Integral Simplices

Feihu Liu, Sihao Tao, Guoce Xin

Testing the unimodular equivalence of two full-dimensional integral simplices can be reduced to testing unimodular permutation (UP) equivalence of two nonsingular matrices. We cond…

math.CO2025

The Sign Pattern Problem for Ehrhart Polynomials

Feihu Liu, Sihao Tao, Guoce Xin

We investigate the sign patterns of coefficients in the Ehrhart polynomial of the Cartesian product between the -th pyramid over the Reeve tetrahedron and the hypercube $[0, n]^…

math.CO2025

Closed-Form Decomposition for Simplicial Cones and PDBarv Algorithm for Lattice Point Counting

Sihao Tao, Guoce Xin, Zihao Zhang

Counting lattice points within a rational polytope is a foundational problem with applications across mathematics and computer science. A key approach is Barvinok's algorithm, whic…