TTT79: Sheffield

The University of Sheffield.

Supported by the London Mathematical Society.

Date

8 June 2011

Speakers

Pokman Cheung (Sheffield)
Equivariant chiral differential operators and associated modules

After an introduction of chiral differential operators (CDOs) on a manifold with a mention of their relation to 'formal loops', I will discuss how they interact with a Lie group action. Let G be a compact Lie group, g its Lie algebra and g' a central extension of the formal loops in g. Under a condition on the equivariant first Pontrjagin class, a G-action on a manifold can be lifted to a (g',G)-action on CDOs. The latter may provide a construction of vector bundles on 'formal loops' (e.g. the spinor bundle).

Ken Deeley (Durham)
Configuration spaces of thick particles on graphs

We discuss topological properties of configuration spaces of particles of positive radius on a metric graph G. In topological robotics, these spaces model the collision-free motion of autonomous robots moving on the guidepath network G. Our main tool for studying these spaces is a piecewise linear (PL) Morse-Bott theory extending the PL Morse theory developed by Bestvina and Brady.

Ieke Moerdijk (Utrecht/Sheffield)
Rectification of infinity-operads

Combined work of Bergner, Joyal-Tierney and Lurie shows the Quillen equivalence between infinity categories and simplicial categories. I will present an extension of this result, establishing a similar equivalence between infinity operads and simplicial operads. The talk is based on joint work with D-C Cisinski.