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 […]
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 […]
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.
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 […]
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 […]
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 […]
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, […]
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 […]
https://youtu.be/zG4xkY8JI1A General Relativity Seminar Speaker: Leo Stein (Mississippi) Title: Resolving memory in numerical relativity, and fixing BMS frames for modeling Abstract: Numerical relativity waveforms serve as ground truth for detection and parameter estimation of binary black hole mergers. Most NR waveforms to date miss memory effects, as they were extracted from simulations using an approximation called extrapolation. I […]
https://youtu.be/SCIi6R_uTZM General Relativity Seminar Speaker: David Fajman (Vienna) Title: Fluid stabilization in slowly expanding cosmological spacetime Abstract: Relativistic fluids are known to form shocks during their evolution from near-homogeneous initial data. In expanding spacetimes, shock formation is suppressed, if the expansion is sufficiently strong. We refer to this effect as fluid stabilization. The occurrence of this phenomenon depends […]
https://youtu.be/cboxkchYFUk General Relativity Seminar Speaker: Daniel Kolb (Max Planck Institute) Title: Quasi-Local Mass in a Binary Black Hole Merger Abstract: One of the major open problems in classical general relativity is how one should define the mass of a finite region of space. In this talk, we will investigate a promising definition proposed by Wang and […]
https://youtu.be/cSgyLwg0v00 General Relativity Seminar Speaker: David Kubiznak (Charles University) Title: Remarkable symmetries of rotating black holes Abstract: It is well known that the Kerr geometry admits a non-trivial Killing tensor and its 'square root' known as the Killing-Yano tensor. These two objects stand behind Carter's constant of geodesic motion as well as allow for separability of test […]