Speaker: 

Siamak Yassemi

Institution: 

University of Tehran and IPM

Time: 

Thursday, January 23, 2020 - 3:00pm to 4:00pm

Host: 

Location: 

RH 306
Let $\mathbb{K}$ be a field and $S = \mathbb{K}[x_1,\ldots,x_n]$ be the

polynomial ring in $n$ variables over $\mathbb{K}$. Suppose that $M$ is a graded $S$-module with minimal free resolution

$$0 \longrightarrow \cdots \longrightarrow \bigoplus_{j}S(-j)^{\beta_{1,j}(M)} \longrightarrow \bigoplus_{j}S(-j)^{\beta_{0,j}(M)} \longrightarrow M \longrightarrow 0.$$

 

The Castelnuovo--Mumford regularity (or simply, regularity) of $M$, denote by ${\rm reg}(M)$, is defined as follows:

$${\rm reg}(M)={\rm max}\{j-i|\ \beta_{i,j}(M)\neq0\}.$$

 

We survey a number of recent studies of the Castelnuovo-Mumford regularity of the ideals related to a graph and their (symbolic) powers. Our focus is on the bounds and exact values for the regularity in terms of combinatorial data from associated graphs. This research program has produced many exciting results and, at the same time, opened many further interesting questions and conjectures.