Since 2002 Perimeter Institute has been recording seminars, conference talks, and public outreach events using video cameras installed in our lecture theatres. Perimeter now has 7 formal presentation spaces for its many scientific conferences, seminars, workshops and educational outreach activities, all with advanced audio-visual technical capabilities. Recordings of events in these areas are all available On-Demand from this Video Library and on Perimeter Institute Recorded Seminar Archive (PIRSA). PIRSA is a permanent, free, searchable, and citable archive of recorded seminars from relevant bodies in physics. This resource has been partially modelled after Cornell University's arXiv.org.
Physics emerged from the twentieth century with two remarkably successful descriptions of nature which stand in striking contrast. Quantum mechanics describes the subatomic realm with intrinsic uncertainties and probabilities. On the other hand, Einstein's general relativity describe gravitational phenomena in an exacting geometric arena. Theoretical physicists have struggled for over fifty years trying to combine these views in a single unified framework. More recently, superstring theory has drawn a huge amount of interest as a leading contender to provide such a unification.
The gauge mediation models with a gravitino mass in the eV range is a
quite attractive scenario which causes no cosmological/astrophysical problems.
The model construction with such a light gravitino is, however, quite challenging
and in most cases ends up with the problems with the suppressed gaugino mass,
the vacuum instability and the Landau pole problems of the Standard Model gauge
Many results have been recently obtained regarding the power of hypothetical closed time-like curves (CTC’s) in quantum computation. Most of them have been derived using Deutsch’s influential model for quantum CTCs [D. Deutsch, Phys. Rev. D 44, 3197 (1991)]. Deutsch’s model demands self-consistency for the time-travelling system, but in the absence of (hypothetical) physical CTCs, it cannot be tested experimentally. In this paper we show how the one-way model of measurement-based quantum computation (MBQC) can be used to test Deutsch’s model for CTCs.
In this talk I shall describe a general formalism based on $AdS_2/CFT_1$ correspondence that allows us to
systematically calculate the entropy, index and other physical observables of an extremal black hole taking into
account higher derivative and quantum corrections to the action. I shall also describe precise microscopic computation of the same
quantities for a class of supersymmetric extremal black holes and compare this with the prediction of $AdS_2/CFT_1$