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.

# Events Archive

## Gravity Initiative Seminar

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

### 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”

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"

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""

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"

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"

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”

### Gravity Initiative Lunch, Elias Most | Flatiron Institute "Constraints on nuclear physics and electromagnetic precursors from neutron star mergers"

With the detection of GW170817 we have observed the first multi-messenger gravitational wave signal from two merging neutron stars. This signal carried a multitude of information about the underlying equation of state (EOS) of nuclear matter, which so far is not known for densities above nuclear saturation.

### Gravity Initiative Lunch, Elena Giorgi | PGI, "The Teukolsky equations in Kerr-Newman spacetime"

Abstract:

### Gravity Initiative Lunch, Barak Zackay | IAS "Detecting Gravitational Waves With Disparate Detector Responses: Two New Binary Black Hole Mergers"

Abstract:

I will describe our continuing work for extracting the most of the LIGO-VIRGO data.

In this talk, I will discuss the process that was used to characterize the impact of non-Gaussian phenomena (so called 'Glitches')

I will then discuss the process that exploited the found properties in order to rank candidates...