Lefschetz properties of monomial ideals and mixed multiplicities
Speaker:
Thiago Holleben, Dalhousie University
Date and Time:
Thursday, May 18, 2023 - 11:00am to 11:45am
Location:
Fields Institute, Room 230
Abstract:
Given a polynomial ring $S$ over a field of characteristic zero and an Artinian ring $A = S/I$ where $I$ is a monomial ideal, we build a new polynomial ring $S_{I}$ with the variables being the nonzero monomials of $A$. For every degree $i$, we define two ideals in $S_{I}$ such that their analytic spread detects the WLP property of $A$ in degree $i$:
1. The jacobian ideal of a hyperplane arrangement, when $I$ is any monomial ideal
2. The edge ideal of a hypergraph, when all the nonzero monomials of $A$ are squarefree.
In particular, when all the nonzero monomials of $A$ are squarefree, we see the connections between birational maps and the failure of WLP in positive characteristics.