**Date & Time:** Tuesday, July 13, 2010, 14:30-15:30.

**Venue:** Ramanujan Hall

**Title:** Regularity of Ext Modules

**Speaker:** Manoj Kummini, Purdue University

**Abstract:** Let S be a polynomial ring and $I \subseteq S$ a homogeneous ideal.
We look at bounds for the Castelnuovo-Mumford regularity of the Ext^i(S/I,
\omega_S) modules where \omega_S is the graded canonical module of S). This
provides some information on the growth of the Hilbert functions the
Ext^i(S/I, \omega_S) modules, which, in turn, describe the growth of the
Hilbert function of the local cohomology modules of S/I. We will show that
reg(Ext^i(S/I, \omega_S)) \leq dim(Ext^i(S/I, \omega_S)), when I is a monomial
ideal. This is joint work with S. Murai.