# Video Library

Since 2002 Perimeter Institute has been recording seminars, conference talks, public outreach events such as talks from top scientists 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 and 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.

Accessibly by anyone with internet, Perimeter aims to share the power and wonder of science with this free library.

## Jet Substructure and Searches for New Physics at the LHC

Thursday Mar 08, 2012
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The LHC is offering our first glimpses of physics at energies above a TeV, allowing us an unprecedented chance to search for very heavy new particles from electroweak compositeness, new gauge forces, extra dimensions, and supersymmetry.  Some of the most interesting signals involve decays into Standard Model particles that we are used to thinking of as "heavy":  W/Z bosons, top quarks, and perhaps Higgs bosons.  However, at genuinely TeV-scale energies, these SM particles with O(100 GeV) mass are produced with relativistic velocities.  Consequently, their own decay products are Lorentz-boos

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## Cosmic Mysteries

Wednesday Mar 07, 2012
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Albert Einstein wrote that “The most beautiful experience we can
have is the mysterious.” In his talk, Dr. Epp will explore how the process of
science—wonder & curiosity coupled with imagination & reasoning—has led
to some of the greatest discoveries and deepest mysteries about the structure,
evolution and origin of the universe.  This
lecture will celebrate the power of science to deepen our sense of cosmic
wonder as we stand before the present-day mysteries of Dark Matter, Dark Energy
and the Big Bang.

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## A Toy Model to Study the Imposition of the Spin Foam Simplicity Constraints

Wednesday Mar 07, 2012
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We introduce an exactly solvable model to test various proposals for the imposition of the spin foam simplicity constraints. This model is a three-dimensional Holst-Plebanski action for the gauge group SO(4), in which the simplicity constraints mimic the situation of the four-dimensional theory. In particular, the canonical analysis reveals the presence of secondary second class constraints conjugated to the primary ones.

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## Demonstration of Self-correcting Quantum Memory in Three Dimensions

Wednesday Mar 07, 2012
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Based on the joint work with Sergey Bravyi, IBM Watson.   We show that any topologically ordered local stabilizer model of spins in three dimensional lattices that lacks string logical operators can be used as a reliable quantum memory against thermal noise. It is shown that any local process creating a topologically charged particle separated from other particles by distance $R$, must cross an energy barrier of height $c \log R$. This property makes the model glassy.

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## Advanced General Relativity - Lecture 16

Wednesday Mar 07, 2012
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## Quantifying Entanglement with Quantum Entropy

Wednesday Mar 07, 2012
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Entropy plays a fundamental role in quantum information theory through applications ranging from communication theory to condensed matter physics.  These applications include finding the best possible communication rates over noisy channels and characterizing ground state entanglement in strongly-correlated quantum systems.  In the latter, localized entanglement is often characterized by an area law for entropy.  Long-range entanglement, on the other hand, can give rise to topologically ordered materials whose collective excitations are robust against local noise.

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## Safe SupeRsymmetry

Wednesday Mar 07, 2012
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Supersymmetry is a popular candidate for the 'model beyond the Standard Model', however minimal versions of it are quite constrained by the first year of data from the LHC. In this talk I will focus on supersymmetry scenarios where the gaugino masses are Dirac rather than Majorana. This seemingly innocuous change has a profound impact on collider bounds -- reducing the bound on (1st and 2nd generation) squark masses by nearly a factor of two. In addition, Dirac gaugino scenarios have amazing flavor properties, smoking gun LHC signals, and cosmological implications.

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## Advanced General Relativity - Lecture 15

Wednesday Mar 07, 2012
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## Quantum Switches and Impossible Time Travels

Tuesday Mar 06, 2012
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This talk presents two results on the interplay between causality and quantum information flow. First I will discuss about the task of switching the connections among quantum gates in a network. In ordinary quantum circuits, gates are connected in a fixed causal sequence.  However, we can imagine a physical mechanism where the connections among gates are not fixed, but instead are controlled by the quantum state of a control system.

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## Constraining the Physics of Inflation

Tuesday Mar 06, 2012
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## Next Public Lecture

Check back for details on the next lecture in Perimeter's Public Lectures Series

## LECTURES ON-DEMAND

### Roger Melko: Perimeter Institute and University of Waterloo

Speaker: Roger Melko