Events Archive

Gravity Initiative Seminar

Special Joint Gravity Group and Gravity Initiative Seminar: Neil Cornish|Montana State| "Gravitational Wave Astronomy: Where we are at, and What’s next”

Fri, May 20, 2022, 12:00 pm

Following the first detection of a binary black hole merger in 2015, the number of gravitational wave events has grown to almost one hundred, including binary neutron star mergers and mixed black hole, neutron star mergers.

PGI Spring Seminar Series|Dan Marrone|University of Arizona|"The Single Aperture Large Telescope for Universe Studies"

Mon, Apr 18, 2022, 12:30 pm

This year, NASA is beginning its search for a Probe-class ($1B) mission to fly in ~2032. This once-per-decade opportunity was endorsed by astro2020 as a way to achieve some of the science promised by the more complex and expensive far-infrared and X-ray missions that were prepared for the decadal survey.

PGI Spring Seminar Series|Marc Casals|CBPF|"Stability Properties and Strong Cosmic Censorship for Rotating Black Hole Spacetimes"

Mon, Apr 4, 2022, 11:30 am

Black holes in the Universe do not exist in isolation but, rather, they are surrounded by matter. It is therefore important to study the stability properties of black holes under matter field perturbations. In this talk we will discuss the stability properties under classical field perturbations of several rotating (Kerr) black hole spacetimes...

PGI Spring Seminar|Zoe Wyatt|University of Cambridge|"Stabilizing Relativistic Fluids on Slowly Expanding Cosmological Spacetimes "

Mon, Mar 28, 2022, 12:30 pm

"On a background Minkowski spacetime, the relativistic Euler equations are known, for a relatively general equation of state, to admit unstable homogeneous solutions with finite-time shock formation. By contrast, such shock formation can be suppressed on background cosmological spacetimes whose spatial slices expand at an accelerated rate.

PGI Spring Seminar Series|Edgar Shaghoulian|University of Pennsylvania|"Applications of the Gravitational Path Integral to Black Holes and Cosmology"

Mon, Feb 28, 2022, 12:30 pm

I will introduce the gravitational path integral and discuss some of its modern applications. Our first application will be to the black hole information paradox, where we will see that nontrivial gravitational saddles are important in exhibiting unitarity of black hole evaporation.

PGI Spring Seminar|J. (Jácome) Armas|University of Amsterdam|"A Stable and Causal Model of Magnetohydrodynamics"

PGI Spring Seminar| Sarah Vigeland |University of Wisconsin-Milwaukee|"Supermassive Black Holes and Merging Galaxies: Low-Frequency Gravitational Wave Detection with Pulsar Timing Arrays"

PGI Spring Seminar|Virtual Series| Jan Sbierski |University of Edinburgh|"The Strong Cosmic Censorship Conjecture and Singularities Inside Rotating Black Holes"

Mon, Feb 7, 2022, 12:30 pm

Abstract: One can paraphrase Penrose’s strong cosmic censorship conjecture as stating that general relativity is generically a deterministic theory. While the full conjecture remains wide open there has long been evidence pointing towards its validity at least for small perturbations of exact rotating Kerr black holes.

PGI Fall Seminar Series| Sam Gralla| University of Arizona|"Surprises in Gravitational Scattering"

Mon, Dec 6, 2021, 12:30 pm

What happens when two masses scatter?  This deceptively simple question has produced a series of surprises that touch on deep issues in general relativity, such as the localizability of gravitational field energy, the notion of asymptotic flatness at timelike infinity, and observability of particle position.

PGI Fall Seminar Series| Aaron Held| Princeton University|"Black Holes Beyond General Relativity: Shadows, Stability, and Nonlinear Evolution"

Mon, Nov 29, 2021, 12:30 pm


Guided by the principles of effective field theory, I will discuss three consecutive avenues to constrain physics beyond General Relativity with black-hole observations.

PGI Fall Seminar Series|Hsin-Yu Chen-Einstein Fellow, MIT|"Gravitational-wave Multimessenger Observations from the Production of Gold to the Expansion of the Universe"

Mon, Nov 22, 2021, 12:30 pm

Over last six years, the LIGO-Virgo detections of gravitational waves from compact binary mergers have underlined their promise as an independent and powerful tool to explore the Universe.

PGI Fall Seminar Series| Stefan Czimek| Brown University|"The Characteristic Gluing Problem of General Relativity"

Mon, Nov 15, 2021, 12:30 pm

In this talk, we introduce and solve the characteristic gluing problem for the Einstein vacuum equations. We prove that obstructions to characteristic gluing come from an infinite-dimensional space of conservation laws along null hypersurfaces for the linearized equations at Minkowski.

PGI Fall Seminar Series| Georgios Moschidis| Princeton University|"The Instability of Anti-de Sitter Spacetime for the Einstein-scalar Field System"

PGI Fall Seminar Series| Keefe Mitman|Caltech| "Gravitational Waves in Numerical Relativity and the Importance of BMS Frames"

PGI Fall Seminar Series|Alejandro Cárdenas-Avendaño|Princeton University|"Quantifying the Unknown Using Electromagnetic and Gravitational Observations of Compact Objects"

Mon, Oct 25, 2021, 12:30 pm

Abstract: Over the past years, electromagnetic and gravitational observations have been used to understand the nature of compact objects and the matter around them.

PGI Virtual Seminar Series | Elisa Maggio, University of Rome "Testing the nature of dark compact objects with gravitational waves"

Mon, Apr 26, 2021, 12:30 pm

Gravitational waves from the coalescence of compact binaries provide a unique opportunity to test gravity in the strong field regime. In particular, the postmerger phase of the gravitational signal is a proxy for the nature of the remnant. 

PGI Virtual Seminar Series | Claude Warnick, Cambridge University "Quasinormal modes of black holes"

Mon, Apr 19, 2021, 12:30 pm

During its ringdown phase a perturbed black-hole produces radiation at characteristic (complex) frequencies, much like the normal frequencies of a guitar string. These quasinormal frequencies carry information about the geometry of the black hole.

PGI Virtual Seminar Series | Marcelo Disconzi, Vanderbilt University "General-relativistic viscous fluids

Mon, Apr 12, 2021, 12:30 pm

The discovery of the quark-gluon plasma that forms in heavy-ion collision experiments provides a unique opportunity to study the properties of matter under extreme conditions, as the quark-gluon plasma is the hottest, smallest, and densest fluid known to humanity.

PGI Virtual Seminar Series | Lydia Bieri, University of Michigan "New Structures in Gravitational Radiation"

Mon, Mar 29, 2021, 12:30 pm

Gravitational waves transport information from faraway regions of the Universe. Since the first detection of gravitational waves by Advanced LIGO in September 2015, several other events have been recorded by the LIGO/VIRGO collaboration.

PGI Virtual Seminar Series | Chris White, PU "Misaligned Accretion Flows and Their Impact on Black Hole Observations"

Mon, Mar 22, 2021, 12:30 pm

A priori it would be surprising if all low-luminosity supermassive black holes, such as those in the centers of M87 and our own galaxy, had accretion disks aligned with their spin.