University of Cambridge > Talks.cam > Isaac Newton Institute Seminar Series > The evolution of L2-Betti numbers

The evolution of L2-Betti numbers

Add to your list(s) Download to your calendar using vCal

If you have a question about this talk, please contact INI IT.

This talk has been canceled/deleted

L2-Betti numbers of Riemannian manifolds were introduced by Atiyah in the 1970s. Cheeger and Gromov extended their scope of definition to all countable discrete groups in the 1980s. Nowadays, there are L2-Betti numbers of arbitrary spaces with arbitrary discrete group actions, of locally compact groups, of quantum groups, of von Neumann algebras, of measured equivalence relations and of invariant random subgroups. Their relation to classical homology comes via a remarkable theorem of Lück, the approximation theorem. We sketch the remarkable extension of the  definition of L2-Betti numbers and present some results about totally disconnected groups. The latter is based on joint work with Henrik Petersen and Andreas Thom. 

This talk is part of the Isaac Newton Institute Seminar Series series.

Tell a friend about this talk:

This talk is included in these lists:

This talk is not included in any other list

Note that ex-directory lists are not shown.

 

© 2006-2024 Talks.cam, University of Cambridge. Contact Us | Help and Documentation | Privacy and Publicity