Forthcoming events in this series


Mon, 07 May 2007
15:45
L3

Local-to-global principles for classifying spaces

Jesper Grodal
(Copenhagen)
Abstract
  In this talk I will show how one can sometimes "uncomplete" the p-completed classifying space of a finite group, to obtain the original (non-completed) classifying space, and hence the original finite group. This "uncompletion" process is closely related to well-known local-to-global questions in group theory, such as the classification of finite simple groups. The approach goes via the theory of p-local finite groups. This talk is a report on joint work with Bob Oliver.  
Mon, 20 Nov 2006
15:45
L3

Characteristic classes of A-infinity algebras

Alastair Hamilton
(Bonn)
Abstract

There is a construction, due to Kontsevich, which produces cohomology classes in moduli spaces of Riemann surfaces from the initial data of an A-infinity algebra with an invariant inner product -- a kind of homotopy theoretic notion of a Frobenius algebra.

In this talk I will describe a version of this construction based on noncommutative symplectic geometry and use it to show that homotopy equivalent A-infinity algebras give rise to cohomologous classes. I will explain how the whole framework can be adapted to deal with Topological Conformal Field Theories in the sense of Costello, Kontsevich and Segal.

Mon, 13 Nov 2006
15:45
L3

Topology of moduli space III

Prof Ulrike Tillmann
(Oxford)
Abstract

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Mon, 30 Oct 2006
15:45
L3

Topology of moduli spaces I

Ulrike Tillmann
Abstract

1. Introduction and survey of the cohomological results

This will be a relatively gentle introduction to the topologist's point of view of Riemann's moduli space followed by a description of its rational and torsion cohomology for large genus.

Mon, 07 Nov 2005
15:45
L3

Differential Operators on Loop Spaces

Andrew Stacey
(Sheffield)
Abstract

This talk will be a tour of a couple of problems in the differential topology of

loop spaces.  We shall do a "compare and contrast" between these problems

and their finite dimensional analogues, with the aim of illustrating some of the

intriguing aspects of infinite dimensional manifolds.

The problems that we shall focus on are those of defining analogues of

differential operators on manifolds, in particular the Dirac and the

(semi-infinite) de Rham operators.