Bar-Ilan Algebra Seminar
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Date: Wednesday, 14 Iyar 5771 // May 18, 2011
 
Time: 10:00 am promptly  

 PLEASE NOTE THE CHANGE OF TIME  

Place: Third floor seminar room, Mathematics building
 
Speaker: Prof. Daniel Lenz (Friedrich-Schiller-Universitaet
         Jena)

 
Title: Order based constructions of groupoids from inverse semigroups
 
Abstract: 
 
We discuss how the universal groupoid of an inverse semigroup introduced
by Paterson can be obtained by a simple order based construction. Along
the way one obtains canonically a reduction of this groupoid. In the case
of  inverse semigroups arising from graphs (respectively, tilings)   this
reduction is the graph groupoid introduced by Kumjian et al.
(respectively, the tiling groupoid of Kellendonk).  We discuss some
topological features of this reduction  as well as the structure of  its
open invariant sets. This can be used to investigate the ideal structure
of an associated reduced $C^*t$-algebra.
 
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Technion Math Net-2 (TECHMATH2)
Editor: Michael Cwikel   <techm@math.technion.ac.il> 
Announcement from: Michael Schein   <mschein@math.biu.ac.il>