Strong Gravity research at Perimeter Institute is devoted to understanding both the theoretical and observational aspects of systems in which gravity is very strong (i.e., spacetime is highly curved or dynamical],. On one hand, this means studying extreme astrophysical systems, like black holes and neutron stars, as well as making and testing predictions for existing and forthcoming gravitational wave detectors, electromagnetic telescopes, and particle astrophysics experiments. On the other hand, it also includes a range of nonastrophysical topics, such as the instabilities of higherdimensional black holes or the dynamics of stronglycoupled quantum field theories (via holography). The goal of strong gravity researcher is to test the validity of Einstein's theory of gravity, constrain proposed alternatives, understand the most extreme astrophysical systems, and investigate the ways in which highly curved or dynamical spacetimes are linked with a range of other problems in fundamental physics.
Format results

34 talksCollection Number C17055
Talk

Quantifying the evidence for black holes with GW and EM probes
Paolo Pani Instituto Superior Tecnico  Departamento de Física

Echoes from the Abyss: Tentative Evidence for PlanckScale Structure at Black Hole Horizons
Jahed Abedi University of Stavanger (UiS)

Improvements on the methods for searching echoes
Julian Westerweck Albert Einstein Institute

A modelindependent search for gravitationalwave echoes
Archisman Ghosh Institucio Catalana de Recerca I Estudis Avancats (ICREA)  Universitat de Barcelona

An alternative significance estimation for the evidence for echoes
Alex Nielsen Albert Einstein Institute

Discussion: Evidence for Echoes
PIRSA:17110074 
Inspiral Tests of Strongfield Gravity and Ringdown Tests of Quantum Black Holes
Kent Yagi University of Virginia

A Recipe for Echoes
Aaron Zimmerman The University of Texas at Austin


PSI 2017/2018  Relativity (Turok)
15 talksCollection Number C17036Talk

PSI 2017/2018  Relativity  Lecture 1
Neil Turok University of Edinburgh

PSI 2017/2018  Relativity  Lecture 2
Neil Turok University of Edinburgh

PSI 2017/2018  Relativity  Lecture 3
Neil Turok University of Edinburgh

PSI 2017/2018  Relativity  Lecture 4
Neil Turok University of Edinburgh

PSI 2017/2018  Relativity  Lecture 5
Neil Turok University of Edinburgh

PSI 2017/2018  Relativity  Lecture 6
Neil Turok University of Edinburgh

PSI 2017/2018  Relativity  Lecture 7
Neil Turok University of Edinburgh

PSI 2017/2018  Relativity  Lecture 8
Neil Turok University of Edinburgh


PSI 2016/2017  Relativity (Turok)
14 talksCollection Number C16010Talk

PSI 2016/2017  Relativity  Lecture 1
Neil Turok University of Edinburgh

PSI 2016/2017  Relativity  Lecture 2
Neil Turok University of Edinburgh

PSI 2016/2017  Relativity  Lecture 3
Neil Turok University of Edinburgh

PSI 2016/2017  Relativity  Lecture 4
Neil Turok University of Edinburgh

PSI 2016/2017  Relativity  Lecture 5
Neil Turok University of Edinburgh

PSI 2016/2017  Relativity  Lecture 6
Neil Turok University of Edinburgh

PSI 2016/2017  Relativity  Lecture 7
Neil Turok University of Edinburgh



EHT 2014
54 talksCollection Number C14041Talk

Welcome to Perimeter Institute and the EHT 2014 Conference
Neil Turok University of Edinburgh


Growth of supermassive black holes and their relationships to their host galaxies
Marta Volonteri Institut d'Astrophysique de Paris

Polarized emission from Black Hole Accretion Disks and Jets
Jonathan McKinney University of Maryland, College Park

Stellar Orbits at the Galactic Center
Andrea Ghez University of California, Los Angeles



Particle Acceleration and Nonthermal Emission in Radiatively Inefficient Accretion Flows
Eliot Quataert University of California, Berkeley




Production of Solar Scalars
AnneChristine Davis University of Cambridge

Probing quantum gravity at all scales
Astrid Eichhorn University of Southern Denmark

Simulating a Quantised Black Hole
Ruth Gregory King's College London

Town Hall  Fundamental aspects of Modified gravity
Adam Solomon, Andrew Tolley, Astrid Eichhorn, Sergey Sibiryakov 
Against Horndeski
Cliff Burgess McMaster University

Extending EFT of inflation/dark energy to arbitrary background with timelike scalar profile
Shinji Mukohyama Yukawa Institute for Theoretical Physics

Quantum Black Holes in the Sky?
34 talksCollection Number C17055The past decade has witnessed significant breakthroughs in understanding the quantum nature of black holes, with insights coming from quantum information theory, numerical relativity, and string theory. At the same time, astrophysical and gravitational wave observations can now provide an unprecedented window into the phenomenology of black hole horizons. This workshop seeks to bring together leading experts in these fields to explore new theoretical and observational opportunities and synergies that could improve our physical understanding of quantum black holes.

PSI 2017/2018  Relativity (Turok)
15 talksCollection Number C17036PSI 2017/2018  Relativity (Turok) 
PSI 2016/2017  Relativity (Turok)
14 talksCollection Number C16010PSI 2016/2017  Relativity (Turok) 

Binary neutron star mergers: from numerical relativity simulations to electromagnetic observables
Eduardo Gutierrez Penn State University
In this talk, I will provide an overview of neutron star (NS) mergers, highlighting the insights gained through numerical relativity simulations. I will mainly focus on the role of the cocoon shock breakout emission as a key early electromagnetic counterpart of NS mergers, with special relevance to events like GW170817. I will explore how the properties of the merger ejecta and the nature of the central engine influence the resulting emission. Additionally, I will present recent advancements in the development of our new general relativistic magnetohydrodynamics (GRMHD) code GRAthena++, and share ongoing research efforts on the evolution of magnetic fields in the postmerger remnant.


Production of Solar Scalars
AnneChristine Davis University of Cambridge
I will first introduce screened modified gravity theories and then discuss the chameleon mechanism. Light scalars can be produced from the sun and detected on earth. I will discuss the production of chameleons, including novel production channels, and discuss potential detection in helioscopes. 
Probing quantum gravity at all scales
Astrid Eichhorn University of Southern Denmark

Simulating a Quantised Black Hole
Ruth Gregory King's College London

Town Hall  Fundamental aspects of Modified gravity
Adam Solomon, Andrew Tolley, Astrid Eichhorn, Sergey SibiryakovLead: Jerome Quintin 
Against Horndeski
Cliff Burgess McMaster University
The Horndeski program is motivated by arguing that scalartensor modifications to gravity should have two properties: effective interactions that are at most secondorder in time derivatives and only a single scalar. I will argue against both of these criteria. First I argue why the lowenergy limit of known wellbehaved theories can have more than twoderivative field equations. Second I argue why the scalartensor interactions most likely to be found competing with gravity at very low energies typically are those with two derivatives, at least when semiclassical methods are justified, and this suggests exploring multiplescalar models. 
Extending EFT of inflation/dark energy to arbitrary background with timelike scalar profile
Shinji Mukohyama Yukawa Institute for Theoretical Physics
I extend EFT of inflation/dark energy to arbitrary background with timelike scalar profile. In this framework a set of consistency relations among EFT coefficients ensures the spatial diffeo invariance. Some applications to will also be discussed.