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A referee found an error in the proof of the Main Theorem ("toric ideals of flow polytopes are generated in degree 3") that we could not fix. More precisely, the proof of Lemma 4.2.(ii) is incorrect. The results on Gr\"obner bases are…

Combinatorics · Mathematics 2011-03-07 Matthias Lenz

The toric ring together with the toric ideal arising from a nested configuration is studied, with particular attention given to the algebraic study of normality of the toric ring as well as the Gr\"obner bases of the toric ideal. One of the…

Commutative Algebra · Mathematics 2011-05-24 Hidefumi Ohsugi , Takayuki Hibi

The toric ideal of a $d$-dimensional flow polytope has an initial ideal generated by square-free monomials of degree at most $d$. The toric ideal of a flow polytope of dimension at most four has an initial ideal generated by square-free…

Commutative Algebra · Mathematics 2021-05-11 Mátyás Domokos , Dániel Joó

It is shown that up to dimension four, the toric ideal of a quiver polytope is generated in degree two, with the only exception of the four-dimensional Birkhoff polytope. As a consequence, B{\o}gvad's conjecture holds for quiver polytopes…

Commutative Algebra · Mathematics 2017-07-04 M. Domokos , Dániel Joó

Let $G$ be a finite graph allowing loops, having no multiple edge and no isolated vertex. We associate $G$ with the edge polytope ${\cal P}_G$ and the toric ideal $I_G$. By classifying graphs whose edge polytope is simple, it is proved that…

Commutative Algebra · Mathematics 2018-08-22 Hidefumi Ohsugi , Takayuki Hibi

In dieser Diplomarbeit werden einige Gradschranken f\"ur Erzeugendensysteme und Gr\"obnerbasen von torischen Idealen von Flusspolytopen bewiesen. Alle torischen Ideale von Flusspolytopen sind im Grad 3 erzeugt. Glatte…

Combinatorics · Mathematics 2011-11-10 Matthias Lenz

We show that the toric ideal of a lattice path polymatroid is generated by quadrics corresponding to symmetric exchanges, and give a monomial order under which these quadrics form a Gr\"obner basis. We then obtain an analogous result for…

Combinatorics · Mathematics 2010-06-15 Jay Schweig

In this paper, we study a class of toric ideals obtained by using some geometric data of ADE trees which are the minimal resolution graphs of rational surface singularities. We compute explicit Gr\"obner bases for these toric ideals that…

Commutative Algebra · Mathematics 2015-12-09 Gülay Kaya , Pınar Mete , Mesut Şahin

In 1980, White conjectured that the toric ideal of a matroid is generated by quadratic binomials corresponding to a symmetric exchange. In this paper, we compute Gr\"obner bases of toric ideals associated with matroids and show that, for…

Commutative Algebra · Mathematics 2020-04-28 Ken-ichi Hayase , Takayuki Hibi , Koyo Katsuno , Kazuki Shibata

Hara, Takemura and Yoshida discuss toric ideals arising from two way subtable sum problems and shows that these toric ideals are generated by quadratic binomials if and only if the subtables are either diagonal or triangular. In the present…

Commutative Algebra · Mathematics 2018-08-22 Hidefumi Ohsugi , Takayuki Hibi

In this paper, we discuss the normality of the toric rings of stable set polytopes, and the set of generators and Gr\"obner bases of toric ideals of stable set polytopes by using the results on that of edge polytopes of finite nonsimple…

Commutative Algebra · Mathematics 2019-07-12 Kazunori Matsuda , Hidefumi Ohsugi , Kazuki Shibata

Let $G$ be a finite connected simple graph and $I_{G}$ the toric ideal of the edge ring $K[G]$ of $G$. In the present paper, we study finite graphs $G$ with the property that $I_{G}$ is generated by quadratic binomials and $I_{G}$ possesses…

Commutative Algebra · Mathematics 2014-05-15 Takayuki Hibi , Kenta Nishiyama , Hidefumi Ohsugi , Akihiro Shikama

In combinatorial commutative algebra and algebraic statistics many toric ideals are constructed from graphs. Keeping the categorical structure of graphs in mind we give previous results a more functorial context and generalize them by…

Commutative Algebra · Mathematics 2011-10-04 Alexander Engstrom , Patrik Noren

We give an explicit formula on the Ehrhart polynomial of a 3-dimensional simple integral convex polytope by using toric geometry.

Combinatorics · Mathematics 2016-05-17 Yusuke Suyama

Every normal toric ideal of codimension two is minimally generated by a Grobner basis with squarefree initial monomials. A polynomial time algorithm is presented for checking whether a toric ideal of fixed codimension is normal.

Commutative Algebra · Mathematics 2008-01-30 Pierre Dueck , Serkan Hosten , Bernd Sturmfels

It is shown that the toric ideal of the centrally symmetric configuration of the order polytope of a finite partially ordered set possesses a squarefree quadratic initial ideal. It then follows that the convex polytope arising from the…

Commutative Algebra · Mathematics 2016-01-08 Takayuki Hibi , Kazunori Matsuda , Hidefumi Ohsugi , Kazuki Shibata

In this note we gather and review some facts about existence of toric spaces over 3-dimensional simple polytopes. First, over every combinatorial 3-polytope there exists a quasitoric manifold. Second, there exist combinatorial 3-polytopes,…

Algebraic Topology · Mathematics 2026-02-10 Anton Ayzenberg

Via the theory of reverse lexicographic squarefree initial ideals of toric ideals, we give a new class of Gorenstein Fano polytopes (reflexive polytopes) arising from a pair of stable set polytopes of perfect graphs.

Commutative Algebra · Mathematics 2019-01-11 Hidefumi Ohsugi , Takayuki Hibi

The universal Gr\"{o}bner basis of $I$, is a Gr\"{o}bner basis for $I$ with respect to all term orders simultaneously. Let $I_G$ be the toric ideal of a graph $G$. We characterize in graph theoretical terms the elements of the universal…

Commutative Algebra · Mathematics 2010-05-25 Christos Tatakis , Apostolos Thoma

It has been conjectured that the toric ideal of the base ring of a discrete polymatroid is generated by symmetric exchange binomials. In the present paper, we give several classes of discrete polymatroids which yield toric ideals generated…

Commutative Algebra · Mathematics 2025-07-17 Takayuki Hibi , Seyed Amin Seyed Fakhari
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