## Algebra and Combinatorics Seminar

**Date: ** November 4, 2022

**Time: ** 3:00PM - 4:00PM

**Location: ** BLOC 302

**Speaker: **Christopher O'Neill , San Diego State University

**Title: ***Numerical semigroups, minimal presentations, and posets*

**Abstract: **A numerical semigroup is a subset S of the natural numbers that is closed under addition. One of the primary attributes of interest in commutative algebra are the relations (or trades) between the generators of S; any particular choice of minimal trades is called a minimal presentation of S (this is equivalent to choosing a minimal binomial generating set for the defining toric ideal of S). In this talk, we present a method of constructing a minimal presentation of S from a portion of its divisibility poset. Time permitting, we will explore connections to polyhedral geometry.
No familiarity with numerical semigroups or toric ideals will be assumed for this talk.