Today

  • Rough solutions of the relativistic Euler equations

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    https://youtu.be/8QfTA8wmChY General Relativity Seminar Speaker: Sifan Yu, Vanderbilt University Title: Rough solutions of the relativistic Euler equations Abstract: I will discuss recent works on the relativistic Euler equations with dynamic vorticity and entropy. We use a new formulation of the equations, which has geo-analytic structures. In this geometric formulation, we decompose the flow into geometric "sound-wave […]

  • Resolving the photon ring

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    https://youtu.be/KCo0iWFox1s General Relativity Seminar Speaker: Shahar Hadar (University of Haifa) Title: Resolving the photon ring Abstract: In the past few years, the Event Horizon Telescope has released the first close-up interferometric images of two supermassive black holes, M87* and SgrA*. It is believed that within these images is embedded a fine, yet-unresolved brightness enhancement called the photon ring. […]

  • CMSA GR Seminar 04.24.23 (1)

    Recent advances in scalar curvature and positive mass theorems

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    https://youtu.be/kGpZ0nRcZRU General Relativity Seminar Speaker: Tin Yau Tsang, University of California Irvine Title: Recent advances in scalar curvature and positive mass theorems Abstract:  First, we have a review of classical tools for studying scalar curvature and positive mass theorem. Then we are going to discuss some advances and new perspectives on these tools which lead […]

  • CMSA GR Seminar 04.27.23

    The localized seed-to-solution method for the Einstein constraints

    Virtual

    https://youtu.be/eGU1AQBcxNw General Relativity Seminar Speaker: Philippe G. LeFloch, Sorbonne University and CNRS Title: The localized seed-to-solution method for the Einstein constraints Abstract: I will discuss advances on asymptotically Euclidian initial data sets and the variational method introduced by J. Corvino and R. Schoen. This talk is based on joint papers with The-Cang Nguyen (Montpellier) and Bruno […]

  • Testing GR with GWs

    CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

    https://youtu.be/Bm3FA2avr4I General Relativity Seminar Speaker: Vitor Cardoso, IST, Lisbon and The Niels Bohr Institute, Copenhagen Title: Testing GR with GWs Abstract: One of the most remarkable possibilities of General Relativity concerns gravitational collapse to black holes, leaving behind a geometry with light rings, ergoregions and horizons. These peculiarities are responsible for uniqueness properties and energy extraction mechanisms that […]

  • CMSA GR Seminar 05.11.23

    Positivity of Static quasi-local Mass in general relativity

    Virtual

    https://youtu.be/b4vyZvml0aw General Relativity Seminar Speaker: Aghil Alaee, Clark University Title: Positivity of Static quasi-local Mass in general relativity Abstract: In this talk, we review results on the PMT of quasi-local masses and prove the positivity of static quasi-local masses with respect to the AdS and AdS Schwarzschild spacetimes.

  • Grey Galaxy’ as the endpoint of the Kerr-AdS super radiant blackhole

    Jefferson 453 17 Oxford St, Cambridge, MA 02138, MA

    General Relativity Seminar Speaker: Suman Kundu (Weizmann Institute) Title: ‘Grey Galaxy’ as the endpoint of the Kerr-AdS super radiant blackhole Abstract: Kerr AdS$_{d+1}$ black holes for $d\geq 3$ suffer from classical superradiant instabilities over a range of masses near extremality. We conjecture that these instabilities settle down into Grey Galaxies (GG)s - a new class of […]

  • Pole skipping, quasinormal modes, shockwaves and their connection to chaos

    https://youtu.be/cxdPO4L4GDk General Relativity Seminar Speaker: Diandian Wang(Harvard University) Title: Pole skipping, quasinormal modes, shockwaves and their connection to chaos Abstract: A chaotic quantum system can be studied using the out-of-time-order correlator (OTOC). I will tell you about pole skipping — a recently discovered feature of the retarded Green’s function — that seems to also know things: things like the Lyapunov […]

  • Quantization of causal diamonds in 2+1 dimensional gravity

    https://youtu.be/TOfxA6N0Eds General Relativity Seminar Speaker: Rodrigo Silva, University of Maryland Title: Quantization of causal diamonds in 2+1 dimensional gravity Abstract: We develop the reduced phase space quantization of causal diamonds in $2+1$ dimensional gravity with a nonpositive cosmological constant. The system is defined as the domain of dependence of a spacelike topological disk with a […]

  • Geometry at Strong coupling for amplitudes/Wilson loops

    https://youtu.be/WQlkQf25np4 General Relativity Seminar Speaker: Lionel Mason (Oxford) Title: Geometry at Strong coupling for amplitudes/Wilson loops Abstract: The amplitude/Wilson loop correspondence identifies planar N=4 super-Yang-Mills amplitudes with certain null polygonal Wilson loops at all the values of the coupling. At strong coupling this equates the amplitude/Wilson loop computed by Alday & Maldacena in terms of […]

  • A Smooth Horizon without a Smooth Horizon

    General Relativity Seminar Speaker: Chethan Krishnan (IISc Bangalore) Title: A Smooth Horizon without a Smooth Horizon Abstract: I will talk about some work that is about to appear, where we note one precise way in which the stretched horizon can simulate a smooth horizon. I will also make an effort to put things in some perspective (brickwalls, […]

  • Tidal Squeezing of Black Holes

    General Relativity Seminar Speaker: Maria Rodriguez (Utah) Title: Tidal Squeezing of Black Holes Abstract: Recent developments indicate that Kerr black holes do not deform when perturbed by a static external gravitational field. Relying on hidden symmetries, compelling progress has been achieved to explain that Love numbers for Kerr black holes vanish. How does the phenomenon of tidal squeezing manifest in broader […]