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.
In string compactifications, Kahler metrics for chiral matter fields are an essential prerequisite for the computation of soft supersymmetry breaking terms. I describe new techniques for computing these in Calabi-Yau string compactifications. This involves deducing the modular behaviour of the Kahler metric from that of the physical Yukawa couplings. Using these techniques I derive Kahler metrics for both KKLT and large-volume models. For the latter case, I discuss two applications.
Weakly interacting massive particles (WIMPs) are excellent candidates
for cold dark matter. After the first millisecond, WIMPs have
decoupled from standard model matter, both chemically and
kinetically, they enter the free streaming regime and the formation
of cosmic structure begins. Another 40 million years pass before the
typical first structures enter the nonlinear regime and collapse to
the first WIMPy halos. Therefore, it has been assumed that structure
formation is insensitive to the WIMP field theory and can be
Realizations of inflation in string theory hold the promise of connecting the theory to observational tests, and at the same time providing new insights for field theory models of inflation. I will report on progress towards realizing inflation on D-branes in type IIB string theory. Moduli stabilization effects generically lead to an eta problem in this scenario, and to analyze the model it is necessary to compute a particular correction to the nonperturbative effects arising on wrapped D-branes.
We consider the hypothesis that quantum mechanics is an approximation to another, cosmological theory, accurate only for the description of subsystems of the universe. Quantum theory is then to be derived from the cosmological theory by averaging over variables which are not internal to the subsystem, which may be considered non-local hidden variables. I will explain the motivation for this view, give some examples of theories of this kind and investigate general conditions for such an approach to succeed.