Seventy-ninth Meeting of the Transpennine Topology Triangle

University of Sheffield
Wednesday 8th June 2011

Supported by the London Mathematical Society  


All talks will be in J11, the usual seminar room on J floor of the Hicks Building.
The morning and afternoon coffee/tea will be served in the I floor common room (I15) of the Hicks Building.
Lunch may be taken in any of several local venues and we expect to visit a nearby restaurant for early-evening dinner.





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.


Everyone who wishes to participate is welcome, particularly postgraduate students. We shall operate the usual criteria for assistance with travel expenses, but beneficiaries will need to complete the standard forms (available from the main TTT page), and should come armed with NI numbers and details of UK bank accounts if they want to complete the form on the day. 

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