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.

The DBI Pseudo-Conformal Universe: Scale Invariance from Spontaneous Breaking of Conformal Symmetry

Saturday May 12, 2012
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The pseudo-conformal scenario is an alternative to inflation in which the early universe is approximately described by a conformal field theory in Minkowski space. Crucially, the cosmological background spontaneously breaks the flat space so(4,2) conformal algebra down to its so(4,1) de Sitter subalgebra, causing conformal-weight-0 fields to acquire a scale invariant spectrum of perturbations. This framework is very general, and its essential features are determined by the symmetry breaking pattern, irrespective of the details of the underlying microphysics.

On a partially Reduced Phase Space Quantisation of General Relativity Conformally Coupled to a Scalar Field

Saturday May 12, 2012

We comment on a certain partially reduced phase space quantisation of general relativity conformally coupled to a scalar field, and its extension to standard model matter fields. The partially reduced phase space is reached by trading the Hamiltonian constraint for the generator of local conformal transformations on all phase space variables, inspired by the ideas of shape dynamics, and constructing conformally invariant connection variables. Furthermore, we review this trading of symmetries from the gauge fixing/unfixing perspective, which is dual to the concept of a linking theory.

Time and a Physical Hamiltonian for Quantum Gravity

Saturday May 12, 2012
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I will describe an approach to the problem of time that uses dust as a time variable. The canonical theory is such that there is a true Hamiltonian with spatial diffeomorphisms as the only gauge symmetry. This feature, and the form of the Hamiltonian, suggest a model for non-perturbative quantum gravity that is computationally accessible using the formalism of loop quantum gravity.

Cosmology and GR Limit of Horova-Lifshitz Gravity

Saturday May 12, 2012
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TBA

Conformal Gravity and Black Hole Complementarity

Friday May 11, 2012
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Emergent Conformal Violation: Does Inflation Like Fundamental Scalar Fields?

Friday May 11, 2012
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We present a new model of inflation which does not rely on fundamental scalar fields.  The theory is a conformally invariant gauge field theory minimally coupled to massless fermions.  At the beginning of inflation, the conformal symmetry is dynamically broken by a BCS condensation of the fermions, leading to a spontaneously violation of conformal symmetry.  A quasi de-Sitter inflationary regime is driven by the interaction between a homogenous plasma dynamo between the gauge, gravitational and condensate field.  Unique observational consequences of this model are twofold : (1) The sourcin

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Emergent Gauge Fields and their Condensation in Quantum Spin Liquids

Friday May 11, 2012
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Large quantum fluctuations in certain quantum spin systems destroy long range magnetic order such as antiferromagnetism. Resulting paramagnetic states are called a quantum spin liquids. These states support emergent gauge fields [1]. Under certain conditions, emergent gauge fields condense in the ground state, leading to a chiral spin liquid state [2]. A condensed magnetic field' for example, correspond to presence of spontaneous circulating spin current or spin chirality'[3].

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Is Nothing Sacred? The Cosmological Pay Off from Breaking Lorentz and Diffeormorphism Invariance

Friday May 11, 2012
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I show how the local Lorentz and/or diffeomorphism invariances may be broken by a varying c, softly or harshly, depending on taste. Regardless of the fundamental implications of such dramas, these  symmetry breakings may be of great practical use in cosmology. They may solve the horizon and flatness problems. A near scale-invariant spectrum of fluctuation may arise, even without inflation. Distinct imprints may be left, teaching us an important lesson: our foundations may be flimsier than we like to think.

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Conformal Cosmology and Physics at Gravitational and Electroweak Scales

Friday May 11, 2012
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New techniques for obtaining the complete set of analytic solutions of the usual cosmological equations continue to shed new light on various aspects of cosmology. This approach, which was developed with a locally Weyl invariant formulation of gravity in 3+1 dimensions, was inspired by the 2T-physics formulation of all physics in 4+2 dimensions.

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The Conformal Method and Solutions of the Einstein Constraint Equations: A Status Report

Friday May 11, 2012
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The Conformal Method (as well as the closely related Conformal Thin Sandwich Method) has proven to be a very useful procedure both for constructing and for parametrizing solutions of the Einstein initial data constraint equations, for initial data sets with constant mean curvature (CMC). Is this true for non CMC data sets as well? After reviewing the CMC results, we discuss what we know and don't know about non CMC initial data sets and the effectiveness of the Conformal Method in handling them.

Next Public Lecture

INGRID WALDRON, DALHOUSIE UNIVERSITY

Tuesday Apr 24, 2018

RECENT PUBLIC LECTURE

Rob Moore: Stanford Institute for Materials and Energy Sciences

Speaker: Rob Moore