# 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.

## Wilson line impurities, flows and entanglement entropy

Tuesday Aug 06, 2019
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## Spins on a Kagome Lattice: Topological Magnons

Tuesday Aug 06, 2019
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In this talk, I will focus on topological aspects and edge states of a spin system on a Kagome lattice. with the anisotropic XXZ and Dzyaloshinskii-Moriya interaction (DMI). I will begin with the rich phase diagram in the classical limit arising as a result of the interplay of the two interaction strengths, followed by a spin-wave analysis in some of these phases.

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## Weyl Anomaly Induced Current and Holography

Tuesday Aug 06, 2019
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We show that when an external magnetic field parallel to the boundary is applied, Weyl anomaly give rises to a new anomalous current transport near the boundary. Similar to the Casimir effect, this transport phenomena has its origin in the effect of the boundary on the quantum fluctuations of the vacuum. The near-boundary current takes universal form for general boundary quantum field theories, which are covariant, gauge invariant, unitary and renormalizable. We verify the universal law of current by studying free QFT and holographic BCFT.

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## Domain Walls in Super-QCD

Tuesday Aug 06, 2019
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Four-dimensional Yang-Mills and (massive) QCD with minimal N=1 supersymmetry are theories with multiple gapped vacua. Therefore, different regions of space can sit in different vacua and be connected by BPS domain walls. I will present a compact 3D worldvolume description of the walls, capable of classifying all possible BPS walls between vacua and of capturing a 2nd order phase transition as the quark mass is varied. Such a proposal will be confirmed by explicit 4D constructions of BPS domain walls, extending the existing literature.

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## Universality at large transverse spin in defect CFTs

Tuesday Aug 06, 2019
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We study the spectrum of defect conformal field theories (CFTs), and show the existence of universal accumulation points in the defect spectrum. This is achieved by obtaining an inversion formula for the bulk to defect OPE, akin to the Lorentzian inversion formula of Caron-Huot for CFTs without defects. We conclude by applying the result in examples and with an outlook.

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## TBD

Tuesday Aug 06, 2019
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## Symmetries and Dualities of Abelian TQFTs

Tuesday Aug 06, 2019
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## Sphere partition functions and Hamiltonian truncation

Friday Aug 02, 2019
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## Anomalies and the Conformal Bootstrap

Wednesday Jul 31, 2019
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## Stable Flat Bands, Topology, and Superconductivity of Magic Honeycomb Network

Tuesday Jul 30, 2019
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We uncover a rich phenomenology of the self-organized honeycomb network superstructure of one-dimensional metals in a nearly-commensurate charge-density wave 1T-TaS${}_2$, which may play a significant role in understanding global topology of phase diagrams and superconductivity. The key observation is that the emergent honeycomb network magically supports a cascade of flat bands, whose unusual stability we thoroughly investigate.

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