Mon, 01 Jun 2009
15:45
L3

The asymptotic geometry of mapping class groups and application

Dr Cornelia Drutu
(Oxford)
Abstract

I shall describe the asymptotic geometry of the mapping class

group, in particular its tree-graded structure and

its equivariant embedding in a product of trees.

This can be applied to study homomorphisms into mapping class

groups defined on groups with property (T) and on lattices in semisimple groups.

The talk is based upon two joint works with J. Behrstock, Sh. Mozes and M. Sapir.

Fri, 23 Oct 2009

11:45 - 12:45
DH 1st floor SR

Anthony Lock and Becky Shipley

OCIAM Internal Seminar
(Oxford)
Abstract

Anthony Lock will speak on "A Column Model of Moist Convection".

Thu, 21 May 2009

12:15 - 13:15
SR1

Universal moduli of parabolic bundles on stable curves

Dirk Schlueter
(Oxford)
Abstract

A parabolic bundle on a marked curve is a vector bundle with extra structure (a flag) in each of the fibres over the marked points, together with data corresponding to a choice of stability condition Parabolic bundles are natural generalisations of vector bundles when the base comes with a marking (for example, they partially generalise the Narasimhan-Seshadri correspondence between representations of the fundamental group and semistable vector bundles), but they also play an important role in the study of pure sheaves on nodal curves (which are needed to compactify moduli of vector bundles on stable curves). Consider the following moduli problem: pairs $(C,E)$ of smooth marked curves $C$

and semistable parabolic bundles $E\rightarrow C$. I will sketch a construction of projective moduli spaces which compactify the above moduli problem over the space of stable curves. I'll discuss further questions of interest, including strategies for understanding the cohomology of these moduli spaces, generalisations of the construction to higher-dimensional base schemes, and possible connections with Torelli theorems for parabolic vector bundles on marked curves.

Tue, 07 Jul 2009

10:00 - 11:00
Gibson 1st Floor SR

OxMOS Team Meeting

K. Koumatos, T. Squires
(Oxford)
Wed, 20 May 2009

15:00 - 16:00
Gibson 1st Floor SR

OxMOS Team Meeting

Y. Sengul, P. Pathmanathan
(Oxford)
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