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.
Effective field theory is an indispensable tool for the analysis of emergent theories, in which we may know little about the UV degrees of freedom of the theory, and still tremendous amount of information can be revealed only by guessing the light degrees of freedom and symmetries. In this talk I will make use of this tool to describe the quantum theory of emergent long strings, open or closed, where the string need not be fundamental (thus not critical), nor it is strictly one dimensional.
There is now a consensus that gamma-ray bursts involve
extraordinary power outputs, and highly relativistic dynamics.
The trigger is probably a binary merger or collapse involving
compact objects. The most plausible progenitors, ranging from
NS-NS mergers to various hypernova-like scenarios, eventually
lead to the formation of a black hole with a debris torus around it.
The various modes of energy extraction from such systems are discussed.
Assuming that you are really (really) strong, what are the biggest objects in the Universe that hold together enough that you could throw them? What are they made of and why are they so big? In this talk, I will show how studies of the large scale structure of the Universe enable us to reconstruct the initial conditions at the Big-Bang and test the fundamental laws of physics.