A **topological groupoid** is a groupoid internal to Top, where this can be chosen to be one’s favourite category of topological spaces.

The classifying space $B X$ of a topological groupoid $X$ is the geometric realisation of the simplicial space which is the nerve of the groupoid.

There is a topological version of Quillen’s Theorem A.

Last revised on April 5, 2009 at 04:07:17. See the history of this page for a list of all contributions to it.