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SUMMARY:Discrete gauge symmetries in discrete orientifolds - Schellekens\,
  AN (National Institute for Subatomic Physics (Nikhef))
DTSTART:20120629T083500Z
DTEND:20120629T091000Z
UID:TALK38783@talks.cam.ac.uk
CONTACT:Mustapha Amrani
DESCRIPTION:We study the origin of discrete gauge symmetries from open str
 ing sector U(1)'s in orientifolds based on rational conformal field theory
 . By means of an explicit construction\, we find an integral basis for the
  couplings of axions and U(1) factors for all simple current MIPFs and ori
 entifolds of all 168 Gepner models\, a total of 32990 distinct cases. We d
 iscuss how the presence of discrete symmetries surviving as a subgroup of 
 broken U(1)'s can be derived using this basis. We apply this procedure to 
 models with MSSM chiral spectrum\, concretely to all known U(3)xU(2)xU(1)x
 U(1) and U(3)xSp(2)xU(1)xU(1) configurations with chiral bi-fundamentals\,
  but no chiral tensors\, as well as some SU(5) GUT models. \n
LOCATION:Seminar Room 1\, Newton Institute
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