Non-very ample configurations arising from contingency tables

Abstract

In this paper, it is proved that, if a toric ideal possesses a fundamental binomial none of whose monomials is squarefree, then the corresponding semigroup ring is not very ample. Moreover, very ample semigroup rings of Lawrence type are discussed. As an application, we study very ampleness of configurations arising from contingency tables.

6 pages, Title changed. References, Lemma etc. added

Cited by in corpus (3)

• Normal cyclic polytopes and cyclic polytopes that are not very ample
• Separation of integer points by a hyperplane under some weak notions of discrete convexity
• Toric rings and ideals of nested configurations