Events Archive

Gravity Initiative Seminar

PGI Virtual Seminar Series | Fani Dosopoulou, "The Merger History of Elliptical Galaxies: Mass Deficit"

Mon, Nov 23, 2020, 12:30 pm

Abstract: The structure and kinematics of galactic nuclei are fossil relics of the merger histories of galaxies and of the interaction between stars and SMBH binaries. Stars ejection during the SMBH binary evolution should reduce a galaxy’s central density and expand its core.

PGI Virtual Seminar Series | Eliot Hijano Cubelos, "Where are BMS symmetries in the flat limit of AdS/CFT?"

Mon, Nov 16, 2020, 12:30 pm

Abstract: A holographic description of physics in Minkowski space is still elusive. A tempting approach is to implement a flat limit from AdS/CFT. Such a limit has not properly been understood, even at the level of the symmetries of the theory; How do BMS symmetries emerge from the flat limit of the asymptotic symmetries of anti-de Sitter space...

PGI Virtual Seminar Series | Carolyn Raithel, "Constraining the Neutron Star Equation of State with Gravitational Wave Events"

PGI Virtual Seminar Series | Jonathan Wing-hong Luk, “Some singular spacetimes in general relativity”

Mon, Nov 2, 2020, 12:30 pm

Abstract: I will describe a few classes of solutions to the Einstein equations whose metrics are singular or highly oscillatory, and discuss the relation between them. The singular solutions include as special examples impulsive gravitational waves and null dust shell solutions.

PGI Virtual Seminar Series | Yakov Shlapentokh-Rothman, "Naked Singularities for the Einstein Vacuum Equations: The Exterior Solution"

Mon, Oct 26, 2020, 12:30 pm

Abstract: We will start by recalling the weak cosmic censorship conjecture.  Then we will review Christodoulou's construction of naked singularities for the spherically symmetric Einstein-scalar field system.

PGI Virtual Seminar Series | Lia Medeiros, IAS "Gravitational Test beyond the First Post-Newtonian Order with the EHT"

Princeton Gravity Initiative | PCTS Workshop, “Exploring Supermassive Black Holes”

Wed, Oct 14, 2020, 11:00 am to Fri, Oct 16, 2020, 2:00 pm

October 14, 11:00 am-2:30 pm EDT (GMT-4) time | Day 1: SMBH-galaxy co-evolution (observations)

Marta Volonteri 11:00-11:30am Xin Liu 11:30-12:00pm

Break 15 min

PGI Virtual Seminar Series | Matthew Heydeman, "Statistical Mechanics of Near-BPS Black Holes from N=4 JT Supergravity"

PGI Virtual Seminar Series | Gabriele Benomio, "A new instability for higher dimensional black holes"

Mon, Sep 21, 2020, 12:30 pm

Abstract: In contrast with the classical stability of stationary, asymptotically flat black holes in four dimensions, some families of higher dimensional black holes suffer from dynamical instabilities.

PGI Virtual Seminar Series | Alex Lupsasca, "The Shape of the Black Hole Photon Ring: A Precise Test of Strong-Field General Relativity"

Mon, Sep 14, 2020, 12:30 pm

We propose a new test of strong-field general relativity (GR) based on the universal interferometric signature of the black hole photon ring. The photon ring is a narrow ring-shaped feature, predicted by GR but not yet observed, that appears on images of sources near a black hole.

Gravity Initiative Lunch, Fani Dosopoulou | PCTS

Gravity Initiative Lunch Seminar, Yakov Shlapentokh-Rothman | Princeton

Gravity Initiative Lunch, Matthew Heydeman | Princeton GI

Gravity Initiative Lunch, Lia Medeiros | IAS

Gravity Initiative Lunch, Martin Lesourd | Harvard BHI “ The Quasi-Local Penrose Inequality and the Hoop Conjecture”

Mon, Mar 9, 2020, 12:30 pm

The Spacetime Inequality of Penrose 1972 says that any slice in any black hole spacetime, the ADM mass of the slice is bounded below by the area of cuts with the event horizon.

Gravity Initiative Lunch, Maxime Van De Moortel | Princeton "The breakdown of weak null singularities inside black holes"

Mon, Mar 2, 2020, 12:30 pm

Abstract: The characterization of singularities inside black holes is a fundamental problem in General Relativity. While the celebrated “mass inflation” scenario suggests that a weakly *singular* Cauchy horizon forms inside generic black holes (near time-like infinity), the global structure of the black hole interior boundary has largely...

Gravity Initiative Lunch, Stephen Adler | IAS "Implications of a Frame-Dependent Dark Energy for the Spacetime Metric and "Hubble Tension""

Mon, Feb 24, 2020, 12:30 pm

Abstract:   I discuss the possibility that the ''dark energy'' that drives the accelerated expansion of the universe arises not from a conventional cosmological constant term in the gravitational action, but rather from a frame-dependent but Weyl scaling invariant action term.

Gravity Initiative Lunch, Bart Ripperda | Princeton/Flatiron "Magnetic reconnection and plasmoid formation in black hole accretion flows"

Mon, Feb 17, 2020, 12:30 pm

Hot spots, or plasmoids, formed due to magnetic reconnection in thin current sheets are conjectured to power frequent bright X-ray and near-infrared flares from supermassive black holes, like Sgr A* in the center of our Galaxy.

Gravity Initiative Lunch, Katerina Chatziioannou | CCA "Studying neutron stars with gravitational waves"

Mon, Feb 10, 2020, 12:30 pm

Neutron stars, the most dense astrophysical bodies we know of, are at the heart of many interesting astrophysical phenomena from their birth in supernova explosions to their deaths in collisions with other dense objects.

Gravity Initiative Lunch, Klaountia Pasmatsiou | CWRU “Finite size effects on the self-force”