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.
I review three challenges faced by attempts to develop a quantum theory of the universe and examine possible relationships between them. 1) The clock ambiguity: The choice of time parameter leads to profound ambiguities. 2) The choice of state: I contrast the de Sitter equilibrium picture with eternal inflation. 3) The Born rule crisis: The born rule is insufficient to construct probabilities in a large multiverse without additional rules or assumptions (as discussed by Don Page).
We propose a holographic description of four dimensional single scalar inflationary universes, in particular asymptotically de Sitter cosmologies and power-law inflation. We show how cosmological observables such as the primordial power spectrum and non-gaussianities are encoded in correlation functions of a three dimensional QFT.
In Randall-Sundrum single-brane (RS-II) model, it was conjectured that there is no
static large black hole localized on the brane based on adS/CFT correspondence. Here we consider the phase diagram of black objects in the models extended from the RS-II model. We propose a scenario for the phase diagram consistent with the classical black hole evaporation conjecture. The proposed scenario indicates the existence of a rich variety of the families of black objects. We present several side evidences that support the whole picture.
We will describe black holes in AdS with hyperbolic horizons, and obtain a holographic description of the region inside the horizon, focusing on the dynamics of the scalar fields in the dual gauge theory. This leads to a proposal for a dual description of D-branes falling through the horizon of any AdS black hole. The proposal uses a field-dependent time reparameterization in the field theory. We relate this reparametrization to various gauge invariances of the theory. Finally, we speculate on information loss and the black hole singularity in this context.
We study generic single-field dark energy models, by a parametrization of the most general theory of their perturbations around a given background, including higher derivative terms. In appropriate limits this approach reproduces standard quintessence, k-essence and ghost condensation. We find no general pathology associated to an equation of state w_Q
I will review the string gas scenario of structure formation, stressing the role which holography plays. I will also discuss another way of obtaining a scale-invariant spectrum of cosmological perturbations (with specific signatures in the bispectrum) which may be realizable in scenarios based on the AdS/CFT correspondence which can resolve the cosmological singularity.