activity
20242026
collaborators

6 papers

math.AC2026

Cartwright--Sturmfelsness of complementary determinantal edge ideals

Koichiro Tani

We introduce complementary determinantal edge ideals. For a graph on vertices, the complementary determinantal edge ideal is generated by the maximal minors of a…

math.AC2026

Algebras with straightening laws on join- or meet-semidistributive lattices

Koji Matsushita, Sora Miyashita, Koichiro Tani

We study algebras with straightening laws on join- or meet-semidistributive lattices. We show that for a join-semidistributive (resp. meet-semidistributive) lattice, meet-distribut…

math.AC2025

Standard multigraded Hibi rings and Cartwright-Sturmfels ideals

Koji Matsushita, Koichiro Tani

In this paper, we introduce standard multigradings on Hibi rings, which are algebras arising from posets. We show that any standard multigrading on a Hibi ring that makes its defin…

math.AC2025

Initial ideals of generic ideals and variations of Moreno-Socías conjecture

Koichiro Tani

It is known that the initial ideals of generic ideals are the same. Moreno-Socías conjectured that the initial ideal of generic ideals with respect to the degree reverse lexicograp…

math.AC2025

Khovanskii bases of subalgebras arising from finite distributive lattices

Akihiro Higashitani, Koji Matsushita, Koichiro Tani

The notion of Khovanskii bases was introduced by Kaveh and Manon. It is a generalization of the notion of SAGBI bases for a subalgebra of polynomials. The notion of SAGBI bases was…

math.AC2024

Non-finitely generated monoids corresponding to finitely generated homogeneous subalgebras

Akihiro Higashitani, Koichiro Tani

The goal of this paper is to study the possible monoids appearing as the associated monoids of the initial algebra of a finitely generated homogeneous -subalgebra of a polyn…