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.
Many-body entanglement, the special quantum correlation that exists among a large number of quantum particles, underlies interesting topics in both condensed matter and quantum information theory. On the one hand, many-body entanglement is essential for the existence of topological order in condensed matter systems and understanding many-body entanglement provides a promising approach to understand in general what topological orders exist.
High-accuracy templates predicted by general relativity for the gravitational waves generated by inspiralling compact binaries (binary star systems composed of neutron stars and/or black holes) have been developed using a mixed multipolar and post-Newtonian (MPN) formalism. In this talk we shall review the foundations of this formalism and its main results, including the equations of motion and radiation from compact binaries up to 3.5PN order.
In my talk I will discuss the static subsector of the black hole effective action in an arbitrary dimension. In particular, the derivation of the induced mass multipoles as a result of an external (static) gravitational field will be elucidated. In 4d these constants vanish, however in general they are non-vanishing in higher dimensions. Moreover, in certain cases they exhibit a (classical) renormalization group flow consistent with the divergences of the effective field theory.
One of the major obstacles in quantum information processing is to prevent a quantum bit from decoherence. One powerful approach to protect quantum coherence is dynamical decoupling. I will present some recent progress of diamond-based quantum information processing using dynamical decoupling. The other promising approach is to use topological quantum systems, which are intrinsically insensitive to local perturbations. I will discuss some ideas to create and probe topological quantum systems.
What is the classical limit of perturbative quantum field
theory?
What have we learned about it since the advent of the EFT
approach to GR?
Recent years have seen the paradigm of effective field theory (EFT) successfully applied to an increasing number of classical systems that range from the gravitational inspiral of compact binaries to hydrodynamics. Many of these systems exhibit dissipation in one form or another, such as radiation reaction or viscous fluid flow, that naturally results from the system being open. This "openness" can manifest as energy leaving the dynamical variables of interest via radiation or heat transfer, for example.
I will discuss magnetic properties of superconductors, first in a model independent way and then by using holographic models. This approach has the advantage of highlighting the generic features of superconducting materials and, at the same time, the predictions of specific models. I will start with the Meissner effect and the vortices. Given the importance of the magnetic field dynamics in these phenomena, I will describe how to introduce a dynamical gauge field in holography.