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.
For thousands of years people have wondered, "Are we alone?" Out of the 500 planets so far known to orbit nearby stars, about 100 transit their host stars, that is, the planet goes in front of its star as seen from Earth. The transiting planets are "goldmines" for astronomers, because the planetary sizes, masses, and atmospheres can be routinely measured. NASA's Kepler Space Telescope is further revolutionizing transiting exoplanet studies with its unprecedented photometric precision. Dr.
Scattering amplitudes in gauge theories and gravity have extraordinary properties that are completely invisible in the textbook formulation of quantum field theory using Feynman diagrams. In the standard approach--going back to the birth of quantum field theory--space-time locality and quantum-mechanical unitarity are made manifest at the cost of introducing huge gauge redundancies in our description of physics.
I will discuss a novel approach to time-dependent background fields of string theory, which allows the identification of configurations which satisfy the conformal invariance conditions to all orders in the Regge slope parameter alpha'.
Gauge/gravity duality, a concept which emerged from string theory,
holds promise for revealing the secrets of certain strongly
interacting real world condensed matter systems. Historically, string
theorists presented their subject as a promising framework for a
quantum theory of gravity. More recently, the AdS/CFT correspondence
and gauge/gravity dualities have emerged as powerful tools for using
what we already know about gravity to investigate the properties of