Abstract
We use basic homotopical methods applied to Lie groups made discrete to prove that the real Euler class of a circle bundle vanishes if and only if the bundle is flat.
Open Access
Flat circle bundles, pullbacks, and the circle made discrete
Received15 Dec 2004
Revised05 Jun 2005
Copyright
Copyright © 2005 Hindawi Publishing Corporation. This is an open access article distributed under the
Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.