Classical Lie algebras contra infinite-dimensional positively graded Lie algebras

by Jan-Erik Roos (Stockholm university)

Wednesday 6 Feb 2013, 14:15 → 16:15 Europe/Stockholm

Room FB53 and Oskar Klein auditorium

Finite-dimensional Lie algebras have a long history going back to Lie, Killing, Elie Cartan, ... I will start with a short survey of their theory. Then I will pass to the main subject of my talk, namely those infinite-dimensional positively graded graded Lie algebras that come up in

Group theory,
Algebraic topology,
Commutative ring theory.

For a long time it seemed impossible to say something in these three cases if you were inspired by the finite-dimensional case. But this has now changed and I will give explicit examples illustrationg this. The phenomena that I will describe have in some cases been found and inspired by computer calculations using a programme liedim which has been written by Clas Löfwall. My main emphasis will be case 1) above, but the precolloquium talk 14.15-15.00 by Alexander Berglund will put more emphasis on the other cases.