English

Toric ideal of matching polytopes and edge colorings

Commutative Algebra 2026-05-20 v3 Combinatorics

Abstract

In the present paper, we investigate the maximal degree of minimal generators of the toric ideal of the matching polytope of a graph. It is known that the toric ideal associated to a bipartite graph is generated by binomials of degree at most 33. We show that this fact is equivalent to a result in the theory of edge colorings of bipartite multigraphs. Moreover, a characterization of bipartite graphs whose toric ideals are generated by quadratic binomials is given. Finally, we discuss the maximal degree of minimal generators of the toric ideal associated to a general graph and give a conjecture.

Keywords

Cite

@article{arxiv.2501.19209,
  title  = {Toric ideal of matching polytopes and edge colorings},
  author = {Kenta Mori and Ryo Motomura and Hidefumi Ohsugi and Akiyoshi Tsuchiya},
  journal= {arXiv preprint arXiv:2501.19209},
  year   = {2026}
}

Comments

14 pages, 9 figures, several typos have been corrected, the grant information and References have been updated