Simon Fraser University
SFU Cosmology Seminars

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Thursday, 4 August 2016, 14:30 in P8445B

Dr. Alexander Vikman (IoP of the Czech Academy of Sciences)

Canonical exorcism for cosmological ghosts

We discuss time-dependent classical and quantum canonical transformation. In particular, we demonstrated that for the quantum canonical transformations the Hamiltonian is transformed as a connection in non-abelian gauge theories. We explicitly construct such quantum and classical transformations which change the sign the Hamiltonian. Hence one can canonically transform a ghost into a field with the correct standard sign in front of the quadratic action. Therefore the usual naive criteria for the presence or absence of ghost-like vacuum instabilities on time-dependent backgrounds are not well physically motivated and the actual information about instabilities is hidden in the interactions.

Seminars in 2015:

2015-10-30 14:30 in C9000 - Mark Halpern (UBC): Measuring the acceleration history of the Universe with CHIME (physics colloquium)
2015-11-06 14:30 in C9000 - John Kormendy (University of Texas at Austin): Supermassive black holes in galaxy nuclei: Coevolution (or not) of black holes and host galaxies (physics colloquium)
2016-03-01 15:00 in P8445B - Gabor Kunstatter (University of Winnipeg): Formation and evaporation of nonsingular black holes in new 2d gravity
2016-03-17 14:30 in P8445B - Francesc Ferrer (Washington University in St Louis): Managing astrophysical uncertainties in dark matter detection
2016-08-04 14:30 in P8445B - Alexander Vikman (IoP of the Czech Academy of Sciences): Canonical exorcism for cosmological ghosts

[ See complete seminar archives | iCal feed ]

Modified by Andrei Frolov <frolov@sfu.ca> on 2023-11-01