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.
In the first part of the talk, I will describe the new large N limit of tensor models, based on the “index” of graphs (in contrast to the standard large N expansion based on the “degree”), and the associated new large D limit of matrix models. This new limit sheds an interesting light on the relation between disordered models à la SYK, tensor models and black holes. In the second part of the talk, I will apply these ideas to discuss the phase diagrams of some strongly coupled matrix quantum mechanics.
Detections of compact binary coalescences with Advanced LIGO and Advanced Virgo are now starting to become routine. However, thereis still considerably more information that can be gleaned from these observations, particularly as detector sensitivity and waveform modelsboth improve. We start by describing the methods currently used in LIGO/Virgo data analysis to determine the mass and spin of the remnant black hole of the binary black hole coalescences.
Can computers think? They can certainly calculate - with staggering speed and ever-increasing power - and they have driven scientific and technological advances that would have been impossible without them. Even so, we would like to believe that, for some puzzles, there's no substitute for old-fashioned human intuition. But this view may be changing.
Several equivalent formulations of quantum error correction condition will be introduced. Subtleties arise
when the error correction conditions hold only approximately. We will discuss an equivalent formulation that is
robust to the approximation error. One can leverage this tool to derive the existence of approximate quantum
error correcting code at low energy subspace of CFT that reproduces aspects of the holographic quantum error
correcting code. Using the same tool, we observe that two operators with greatly differing complexity approximately
String theory provides us with 8d supersymmetric gauge theories with gauge algebras su(N), so(2N), sp(N), e_6, e_7 and e_8, but no construction for so(2N+1), f_4 and g_2 is known. If string theory is universal in 8 dimensions, this pattern requires explanation. I will show that the theories for f_4 and so(2N+1) have a global gauge anomaly in flat space, while g_2 does not have it. Surprisingly, we also find that the sp(N) theories, arising from example from O7^+ planes in string theory, have a subtler gauge anomaly.
Gravitational lensing of the cosmic microwave background has emerged as a powerful cosmological probe, made possible by the development and characterization of nearly-optimal estimators for extracting the lensing signal from temperature and polarization maps. One can ask whether similar tools can be applied to upcoming "intensity maps" of emission lines at other wavelengths (e.g. 21cm). In this talk, I will present recent work in this direction, focusing in particular on the impact of gravitational nonlinearities on standard quadratic lensing estimators.
Microwave Kinetic Inductance Detectors, or MKIDs, are superconducting detector arrays that can measure the energy and arrival time of individual optical through near-IR photons without read noise or dark counts. I will discuss our recent work and results from the first two MKID Integral Field Spectrographs (IFSs) for high contrast imaging, DARKNESS/SDC at the P
In this talk I will describe joint work in progress with Andre Henriques to construct examples of Graeme Segal's functorial definition of 2d chiral conformal field theory. While Segal's definition originated in the 1980's, constructive aspects of the theory continue to be challenging, especially with regard to higher genus surfaces. I will motivate and introduce Segal's definition, and describe a new approach to constructing examples using von Neumann algebras.
I show that dark matter abundance can be set by the decoupling of inelastic scatterings instead of annihilations. Coscattering points to dark matter that is exponentially lighter than the weak scale and has a suppressed annihilation rate, avoiding constraints from indirect detection. The late decays of the states into which dark matter upscatters, can lead to observable distortions to the blackbody spectrum of the cosmic microwave background.
Check back for details on the next lecture in Perimeter's Public Lectures Series