# 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.

## Cosmology and fundamental physics with FRBs

Wednesday Sep 04, 2019
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FRBs are the only known sources of extragalactic coherent radiation, that show interference phenomena after traveling over cosmological distances. The interferometric probe allows equivalent strain measurements of $h\sim 10^{-26}$, opening new windows for gravitational wave detection, dark matter properties, and emission physics. I describe new directions, theoretical and observational tools, and current and future experiments.

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## PSI 2019/2020 - Relativity (Kubiznak) - Lecture 2

Wednesday Sep 04, 2019
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## Gravitational wave standard sirens

Wednesday Sep 04, 2019
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## PSI 2019/2020 - Quantum Theory (Branczyk) - Lecture 2

Wednesday Sep 04, 2019
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## Discussion: Where in the Cosmos should we look for novel physics?

Tuesday Sep 03, 2019
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## Operational Causality in Spacetime

Tuesday Sep 03, 2019
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The no-signalling principle, preventing superluminal communication and the consequent logical paradoxes, is typically formulated within the information-theoretic framework in terms of admissible correlations in composite systems. In my talk, I will present its complementary incarnation associated with dynamics of single systems subject to invasive measurements. The `dynamical no-signalling principle' applies to any theory with well defined rules of calculating detection statistics in spacetime.

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## Real-space recipes for general topological crystalline states

Tuesday Sep 03, 2019
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Topological crystalline states are short-range entangled states jointly protected by onsite and crystalline symmetries. While the non-interacting limit of these states, e.g., the topological crystalline insulators, have been intensively studied in band theory and have been experimentally discovered, the classification and diagnosis of their strongly interacting counterparts are relatively less well understood. Here we present a unified scheme for constructing all topological crystalline states, bosonic and fermionic, free and interacting, from real-space "building blocks" and "connectors".

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## Weak Gravity Conjecture From Amplitudes’ Positivity

Tuesday Sep 03, 2019
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I will show how to derive new positivity bounds for scattering amplitudes in theories with a massless graviton in the spectrum in four spacetime dimensions. The bounds imply that extremal black holes are self-repulsive, M/|Q|

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## Gravitational waves in the inhomogeneous Universe

Tuesday Sep 03, 2019
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The discovery of gravitational waves from a binary black hole merger in

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## New Physics in the Rayleigh-Jeans tale of the CMB and cosmic 21cm signal

Tuesday Sep 03, 2019
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