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.
A serious shortcoming of spinfoam loop gravity is the absence of matter.
I present a minimal and surprisingly simple coupling of a chiral fermion field in the framework of spinfoam quantum gravity.
This result resonates with similar ones in early canonical loop theory: the naive fermion hamiltonian was found to be just the extension of the simple
It is argued that the correct quantization of a scalar field theory in de Sitter spacetime involves a de Sitter invariant state which is not the Bunch-Davies vacuum. A novel but natural de Sitter invariant alternative exists and it is suggested that this and is the prefered state for scalar field theories. The argument is based on the exact solution of an interacting scalar field theory.
In the context of the AdS/CFT correspondence, I will discuss model-independent properties shared by bulk theories of gravity with consistent dual descriptions. I will then discuss the prospects of extending these ideas to non-conformal theories, in particular to attempts to realize cosmological theories holographically. I will address the status of in-principle falsifiability of various holographic proposals through internal consistency conditions of the boundary theory.
FRW/CFT duality is a proposal for a holographic dual description for universe created by bubble nucleation. For (3+1) dimensional universe, the dual theory is defined on 2-sphere at the boundary of open universe. I will study correlation functions and explain essential features of FRW/CFT duality: One bulk field corresponds to a tower of CFT operators The boundary theory contains 2D gravity, and the Liouville field plays the role of time. Energy-momentum tensor has dimension 2, as required from the 2D conformal symmetry.
I review different approaches to the kinematics and dynamics of (hyper)elasticity in GR, and describe one that is now being implemented in joint work with Ian Hawke.
Nonlinear numerical relativistic elasticity may be necessary for simulations including neutron star crusts. Basic simulations of large deformations in relativistic elastic matter will be detailed, and issues necessary for more realistic simulations covered. This work is in collaboration with Carsten Gundlach.
An attempt at describing some of the shortcomings in our present understanding of cosmology.
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