BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:The Topology of Contextuality - Kohei Kishida (University of Oxfor
 d)
DTSTART:20150618T131500Z
DTEND:20150618T141500Z
UID:TALK59846@talks.cam.ac.uk
CONTACT:William Matthews
DESCRIPTION:Contextuality is a key feature of quantum mechanics that provi
 des an important non-classical resource for quantum information and comput
 ation. Recently\, Abramsky and Brandenburger have used sheaf theory to giv
 e a unified treatment of contextuality in quantum theory\, subsuming no-go
  results such as Bell-type non-locality and the Hardy paradox. We can use 
 this approach to show how an important class of contextuality arguments ha
 s a topological origin. More specifically\, we show that 'all-vs-nothing' 
 proofs of contextuality\, such as the well-known Mermin-GHZ argument\, are
  witnessed by cohomological obstructions.
LOCATION:MR13\,  Centre for Mathematical Sciences\, Wilberforce Road\, Cam
 bridge
END:VEVENT
END:VCALENDAR