 
Summary: UNIVERSITY OF CALIFORNIA, SANTA BARBARA
BERKELEY ˇ DAVIS ˇ IRVINE ˇ LOS ANGELES ˇ MERCED ˇ RIVERSIDE ˇ SAN DIEGO ˇ SAN FRANCISCO
CSANTA BARBARA ˇ SANTA CRUZ
Geometry, Topology, and Physics Seminar
The Moduli of Sheaves and
"Counting Invariants" for CalabiYau Threefolds
David Morrison
UCSB
Friday, November 13th, 2008, 4:00 p.m.
Room 6635 South Hall
Abstract: We will continue our discussion of stability and moduli spaces in algebraic
geometry, focussing on a particular problem: the moduli of sheaves on a certain
CalabiYau threefold known as the "resolved conifold". We will explain the recent
results of Nagao and Nakajima on this problem, as well as describing the connection
with certain kinds of "counting invariants" on this CalabiYau threefold (related to
the counting of BPS states in physics). There are many different ways to evaluate
these counting invaraints, which (as we shall explain) are related by a "wallcrossing
formula."
Information about future meetings of this seminar can be found at
http://www.math.ucsb.edu/~malmendier/GTPseminar/
