# 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.

## Uncovering the nature of dark matter with stellar streams in the Milky Way

Tuesday Sep 25, 2018
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Stars orbiting in the halo of our galaxy, the Milky Way, are a window into the distribution of dark matter. In particular, tidally disrupted star clusters, which produce thin stellar streams, are optimal tracers of matter. Based on a Fisher-information calculation, we expect that the current data on the known Milky Way streams should constrain the radial profile and the shape of the inner halo to a precision of a few percent. In addition, stellar streams retain a detailed record of the matter field on small scales.

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## Towards a categorification of a projection from the affine to the finite Hecke algebra in type A

Monday Sep 24, 2018

Work of Bezrukavnikov on local geometric Langlands correspondence and works of Gorsky, Neguţ, Rasmussen and Oblomkov, Rozansky on knot homology and matrix factorizations suggest that there should be a categorical version of a certain natural homomorphism from the affine Hecke algebra to the finite Hecke algebra in type A, sending basis lattice elements on the affine side to Jucys-Murphy elements on the finite side.

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## Langlands duality and self-duality for Hitchin systems

Monday Sep 24, 2018
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I will sketch why self-dual versions of the moduli of G-Higgs bundles are expected to arise physically from the study of 4d theories of class S. I will then describe an extension of the Langlands duality results of Hausel-Thaddeus (G=SL(n)) and Donagi-Pantev (arbitrary reductive G) that yields self-dual moduli spaces as a corollary.

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## Computational Physics - Lecture 4

Friday Sep 21, 2018
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## PSI 2018/2019 - Quantum Theory - Lecture 14

Friday Sep 21, 2018
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Summary info-graphic, no-cloning, quantum teleportation

## PSI 2018/2019 - Relativity - Lecture 15

Friday Sep 21, 2018
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Black hole thermodynamics, Euclidean trick, Unruh radiation, Hawking-Page transition

## Toward AGT for general algebraic surfaces

Thursday Sep 20, 2018
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The Alday-Gaiotto-Tachikawa correspondence connects gauge theory on a fourfold with conformal field theory. We are interested in a certain algebro-geometric incarnation of this framework, where the fourfold is an algebraic surface and instantons/differential geometry are replaced with sheaves/algebraic geometry. In this talk, we will present a certain approach to AGT that yields partial results for quite general surfaces, and ask questions about what still needs to be done to state and prove the full correspondence in the language of algebraic geometry.

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Thursday Sep 20, 2018
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I will discuss certain irrelevant operator deformations of holographic conformal field theories that define a one parameter family of quantum field theories which are thought to be dual to quantum gravity in finite regions.
Some examples include the "$T\bar{T}$ deformation of two dimensional holographic CFTs, its generalisations and higher dimensional cousins.

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## PSI 2018/2019 - Quantum Theory - Lecture 13

Thursday Sep 20, 2018
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Realistic postulates of QM (Church of the Llarger Hilbert space)

## PSI 2018/2019 - Relativity - Lecture 14

Thursday Sep 20, 2018
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Black holes: Dark stars, Rindler space analogy, Kruskal extension, Astrophysical BHs

## 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