activity
20242026
collaborators

9 papers

math.CO2026

Minkowski decomposability of symmetric edge polytopes

Akihiro Higashitani, Aki Mori

In this paper, we study the Minkowski decomposability of symmetric edge polytopes of a finite simple graph on vertex set . More precisely, we give a complete cha…

math.CO2026

A matroidal criterion for flow polytopes to be order polytopes

Akihiro Higashitani, Hidefumi Ohsugi

Flow polytopes of directed acyclic graphs form a central class of lattice polytopes in algebraic, geometric, and enumerative combinatorics. Order polytopes are one of the best unde…

math.CO2026

Characterization and chromatic number of triangle-free graphs with diameter 2

Akihiro Higashitani, Diogo Kendy Matsumoto, Naoki Matsumoto

In this paper, we consider triangle-free graphs with diameter 2. If a triangle-free graph with diameter 2 is not isomorphic to a star, then the radius of is also 2, where s…

math.CO2026

On the Ehrhart Theory of Generalized Symmetric Edge Polytopes

Robert Davis, Akihiro Higashitani, Hidefumi Ohsugi

The symmetric edge polytope (SEP) of a (finite, undirected) graph is a centrally symmetric lattice polytope whose vertices are defined by the edges of the graph. SEPs have been stu…

math.RT2025

Fans and polytopes in tilting theory III: Classification of convex -fans of rank 3

Toshitaka Aoki, Akihiro Higashitani, Osamu Iyama +2

The -fan of a finite dimensional algebra is a non-singular fan in its real Grothendieck group, defined by tilting theory. If the union of the simplices…

math.CO2025

Order polytopes of graded posets are gamma-effective

Alessio D'Alì, Akihiro Higashitani

Order polytopes of posets have been a very rich topic at the crossroads between combinatorics and discrete geometry since their definition by Stanley in 1986. Among other notable r…