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.
Dualities appear in nearly all disciplines of physics and play a central role in statistical mechanics and field theory. I will discuss in a pedagogical way our recent findings motivated by a quest for a simple unifying framework for the detection and treatment of dualities.
Is there a theory yet to be discovered that underlies quantum theory and explains its structure? If there is such a theory, one of the features it will have to explain is the central role of complex numbers as probability amplitudes. In this talk I explore the physical meaning of the statement “probability amplitudes are complex” by comparing ordinary complex-vector- space quantum theory with the real-vector-space theory having the same basic structure.
After defining the Regge limit of the CFT four point function, we shall study the Regge theory that controls the high energy behavior of four point function. In AdS/CFT we can test the Regge theory predictions both at weak and strong coupling. At weak coupling, the leading Regge pole is the well known hard pomeron of perturbative gauge theories. At strong coupling, the leading Regge pole comes from the graviton's Regge trajectory in string theory
In his brilliant article "Against 'Measurement'", John Bell famously
argued that the word has had such a damaging effect on the discussion,
that it should now be banned altogether in quantum mechanics. But in
the beginning was the word, and the word is still with us. Indeed,
David Mermin responded In Praise of Measurement that within the field
of quantum computer science the concept of measurement is precisely
defined, unproblematic, and forms the foundation of the entire
subject, a verdict reaffirmed by the development of measurement-based
Two possible explanations for the type SNe Ia supernovae observations are a nonlinear, underdense void embedded in a matter dominated Einstein-de Sitter spacetime or dark energy in the ?CDM model. Both of these alternatives are faced with Copernican fine-tuning problems. A case is made for the void scenario that avoids introducing undetected dark energy.