Fifty-fourth meeting of the Transpennine Topology Triangle

Department of Pure Mathematics
University of Sheffield
Monday, 24th April 2006

This will be a working meeting. There will therefore be the usual time for participant discussion.


We expect to go to eat nearby, soon after the last talk.


Vitaliy Kurlin:
Classical Baker-Campbell Hausdorff formula gives a recursive way to compute Z=log(exp(X)exp(Y)) via commutators of X and Y. The series Z lives in the free Lie algebra L generated by X and Y. The first aim of the talk is to present a closed compressed version of Baker-Campbell-Hausdorff formula in the quotient L/[[L,L],[L,L]]. This result turned out to be a powerful tool for solving exponential equations in Lie algebras. The compressed formula allowed us to solve completely complicated equations defining compressed Drinfeld associators and involving 5 and 6 exponentials. The second aim is to apply the compressed formula to the Lie algebra of formal vector fields on the real line. The enveloping algebra of the above Lie algebra is isomorphic to the Landveber-Novikov algebra of cohomological operations in cobordisms.

Anyone who wishes to participate is welcome: we shall operate the usual arrangements for assistance with travel expenses. We expect to assemble for tea and coffee in I15, Floor 5, from 11.00 am until the first talk. Each lecture will take place in Room J11 of the Hicks Building, Hounsfield Road, Sheffield.
Tea and Coffee will be served in the common room I15.
For further information email John Greenlees, (or John Hunton or Nige Ray if you are interested, so we can make approximately the right amount of tea and coffee.

How to get there

From the rail station, you can catch the Number 60 bus, and get off where it crosses the ring road. Or take the supertram to the University stop. There is more information at School of Mathematics and Statistics Homepage
The meeting is partially supported by a Scheme 3 grant from the London Mathematical Society.

Escape routes

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