Video Library

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.

Using Large-Scale Structure and CMB Observations to Probe the Properties of Dark Energy

Wednesday May 27, 2009
Speaker(s):

Cosmologists are struggling to understand why the expansion rate of our universe is now accelerating. There are two sets of explanations for this remarkable observation: dark energy fills space or general relativity fails on cosmological scales. If dark energy is the solution to the cosmic acceleration problem, then the logarithmic growth rate of structure $dlnG/dlna = \Omega^\gamma$, where $\Omega$ is the matter density independent of scale in a dark matter plus dark energy model.

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Gravitational aether as a solution to the CC problem and more!

Wednesday May 27, 2009
Speaker(s):

Is the cosmological constant a nonlocal quantum residue of discreteness of the causal set type?

Wednesday May 27, 2009
Speaker(s):

The currently accelerating Hubble expansion is in accord with the old heuristic prediction, from causal set theory, of a fluctuating and ever-present cosmological "constant''. More recently, a phenomenological model based on certain of the ideas behind the prediction has been devised, but it remains incomplete. I will review these developments and also mention a possible consequence for the dimensionality of spacetime.

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Dynamics and the Cosmological Constant Problem

Wednesday May 27, 2009
Speaker(s):

TBA

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Is there Eternal Inflation in the Cosmic Landscape ?

Wednesday May 27, 2009
Speaker(s):

TBA

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Zero cosmological Constant from Normalized General Relativity

Tuesday May 26, 2009
Speaker(s):

Normalizing the Einstein-Hilbert action by the volume&nbsp;functional&nbsp;makes the theory invariant under constant&nbsp;shifts in the Lagrangian.&nbsp;The field equations then resemble unimodular gravity whose&nbsp;otherwise&nbsp;arbitrary cosmological constant is now determined as a&nbsp;Machian&nbsp;universal&nbsp;average. We first prove that an empty space-time is necessarily flat,&nbsp;and then demonstrate, by invoking the scalar field paradigm,&nbsp;that the cosmological constant is actually zero.

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Observational Evidence for Cosmological-Scale Extra Dimensions

Tuesday May 26, 2009
Speaker(s):

TBA

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Massive gravity in 3-D and the Chern-Simons-Proca theory

Tuesday May 26, 2009
Speaker(s):

TBA

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Modified gravity, degravitation and equivalence principle

Tuesday May 26, 2009

TBA

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Cascading Gravity and the Cosmological Constant

Tuesday May 26, 2009
Speaker(s):

TBA

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Speaker: Vilhelm Bohr