nLab
topological groupoid

Context

Higher geometry

Topology

Contents

Definition

General

A topological groupoid is an internal groupoid in the category Top.

So this is a groupoid with a topological space of objects and one of morphisms, and all structure maps (source, target, identity, composition) are continuous maps.

A topological groupoid CC is called an open topological groupoid is the source map s:MorCObjCs : Mor C \to Obj C is an open map.

It is called an étale groupoid if in addition ss is a local homeomorphism.

Revised on August 14, 2013 13:44:25 by Urs Schreiber (24.131.18.91)