The Lie group of bisections of a Lie groupoid
  In this article we endow the group of bisections of a Lie groupoid with compact base with a natural locally convex Lie group structure. Moreover, we develop thoroughly the connection to the algebra of sections of the associated Lie algebroid and show for a large class of Lie groupoids that their groups of bisections are regular in the sense of Milnor. 
Alexander Schmeding, Christoph Wockel
math.DG math.GR