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.
Determining causal relationships is central to scientific understanding. Knowledge of such relations permit us not only to predict how a system will behave naturally, but also how it would behave under different hypothetical circumstances, including those where we exert control over some component. In the context of quantum theory, the problem of figuring out what causes what is particularly vexing.
I will discuss the state of particle physics today and emphasize the implications of the discovered H-boson in high energy physics and cosmology and the connections with the future discovery and precision machines and observatories world-wide.
We will briefly review the issue of "information loss" during the Hawking evaporation of a black hole, and argue that the quantum dynamical reduction theories, which have been developed to address the measurement problem in quantum mechanics, possess the elements to diffuse the ``paradox” at the qualitative and at the quantitative level, leading to what seems to be an overall coherent picture.
The QCD axion is a curious Dark Matter candidate, having a mass like the neutrino, but behaving as Cold Dark Matter. I will review how this occurs, and discuss the interesting question of whether WIMPs could be distinguished from axions with Large Scale Structure data.
The properties of a strange metal fermion model with infinite-range
interactions turn out to be closely related to those of charged black holes
with AdS2 horizons. I show that a microscopic computation of the ground
state entropy density of the fermion model yields precisely the Bekenstein-Hawking
entropy density of the black hole. The fermion model is UV finite and has no supersymmetry
Although the inflationary predictions for the primordial power spectrum of density inhomogeneities seem very successful, there is an obscure part in our understanding of the emergence of the seeds of cosmic structure: How does a universe which at one pint in time is described by a state that is fully homogeneous and isotropic, evolve into a state that is not, given that the dynamics does not contain any source for the undoing of such symmetry?