MG12 - Talk detail |
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Participant |
MELAS, EVANGELOS | |
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Institution |
BHC (UNIV. OF WALES), 2 RETHYMNOY St, , ATHENS 10682, TECHNOLOGICAL INST.OF LAMIA DEP. OF INORMATICS LAMIA 35100 ATHENS - GEORGIOU BOUZIANI 23 - ATHENS - DAFNI - Greece | |
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Session |
Talk |
Abstract |
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SQG1 |
RESULTS ON THE REPRESENTATION THEORY OF H(2,2) |
The ordinary Bondi-Metzner-Sachs (BMS) group B is that subgroup of the group of general diffeomorphisms in General Relativity which preserves the asymptotic form of the metric in null directions in a class of asymptotically flat space-times which model bounded gravitational sources which emit gravitational radiation for a finite period of time. As such, B is the best candidate for the universal symmetry group of General Relativity. However, in studying quantum gravity, space-times with signatures other than the usual Lorentzian one, and complex space-times, are frequently considered. Generalisations of B appropriate to these other signatures have been defined earlier. B(2, 2) is the generalisation of B appropriate to the ultrahyperbolic signature (+,+,−,−). The representation theory of B(2, 2) is compared with the representation theory of one of its subgroups H(2,2). |