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

Collection Number C24007

Puzzles in the Quantum Gravity Landscape: viewpoints from different approaches
34 talksCollection Number C23033Talk

Lessons of the Effective Field Theory Treatment of General Relativity
John Donoghue University of Massachusetts Amherst

Positivity Bounds and Effective Fields Theories (A Review)
Andrew Tolley Imperial College London

Holography and its implications for quantum gravity  VIRTUAL
Johanna Erdmenger University of Würzburg


Piecing Together a Flat Hologram
Sabrina Pasterski Perimeter Institute for Theoretical Physics

Open Discussion with today's speakers (Donoghue, Erdmenger, Montero, Pasterski, Tolley)

John Donoghue University of Massachusetts Amherst

Johanna Erdmenger University of Würzburg

Miguel Mlontero IFT Madrid

Sabrina Pasterski Perimeter Institute for Theoretical Physics

Andrew Tolley Imperial College London


Panel Discussion  Strengths and limitations of EFT (Donoghue, Knorr, Montero, Quevedo, Tolley)

John Donoghue University of Massachusetts Amherst

Miguel Mlontero IFT Madrid

Fernando Quevedo University of Cambridge

Carlo Rovelli Centre de Physique Théorique

Andrew Tolley Imperial College London


Status, perspective and three challenges in the asymptoticsafety paradigm for quantum gravity  VIRTUAL
Astrid Eichhorn University of Southern Denmark


Quantum Simulators of Fundamental Physics
23 talksCollection Number C23019Talk


Simulating onedimensional quantum chromodynamics on a quantum computer: Realtime evolutions of tetra and pentaquarks
Christine Muschik Institute for Quantum Computing (IQC)


Five short talks  see description for talk titles

Barbara Soda Perimeter Institute for Theoretical Physics

Dalila Pirvu Perimeter Institute for Theoretical Physics
 Leonardo Solidoro, Pietro Smaniotto, Kate Brown


First observations of false vacuum decay in a BEC
Ian Moss Newcastle University

Building Quantum Simulators for QuFTs
Jorg Schmiedmayer Technical University of Vienna


Language models for simulating the dynamics of quantum systems
Juan Carrasquilla Vector Institute for Artificial Intelligence


Gravitational Waves Beyond the Boxes II
15 talksCollection Number C22013Talk

Welcome and Opening Remarks

William East Perimeter Institute for Theoretical Physics

Reed Essick Canadian Institute for Theoretical Astrophysics (CITA)

Luis Lehner Perimeter Institute for Theoretical Physics

Daniel Siegel University of Greifswald

Suvodip Mukherjee Tata Institute of Fundamental Research (TIFR)

Huan Yang University of Guelph


Measure the cosmic expansion history of the Universe using GW sources
Jonathan Gair Max Planck Institute for Gravitational Physics (Albert Einstein Institute)

Crosscorrelation technique in GW cosmology
Benjamin Wandelt Institut d'Astrophysique de Paris

Matter in Extreme Conditions
Katerina Chatziioannou California Institute of Technology (Caltech)

Matter Effects in Waveform Models
Geraint Pratten University of Birmingham

Dark matter, PBHs, boson clouds
Salvatore Vitale Massachusetts Institute of Technology (MIT)

Multiband GW observation from the thirdgeneration detectors
HsinYu Chen Massachusetts Institute of Technology (MIT)



PSI 2019/2020  Gravitational Physics
15 talksCollection Number C20004Talk

PSI 2019/2020  Gravitational Physics  Lecture 1
Ruth Gregory King's College London

PSI 2019/2020  Gravitational Physics  Lecture 2
Ruth Gregory King's College London

PSI 2019/2020  Gravitational Physics  Lecture 3
Ruth Gregory King's College London

PSI 2019/2020  Gravitational Physics  Lecture 4
Ruth Gregory King's College London

PSI 2019/2020  Gravitational Physics  Lecture 5
Ruth Gregory King's College London

PSI 2019/2020  Gravitational Physics  Lecture 6
Ruth Gregory King's College London

PSI 2019/2020  Gravitational Physics  Lecture 7
Ruth Gregory King's College London

PSI 2019/2020  Gravitational Physics  Lecture 8
Ruth Gregory King's College London


PSI 2019/2020  Relativity (Kubiznak)
15 talksCollection Number C19039Talk


PSI 2019/2020  Relativity (Kubiznak)  Lecture 2
David Kubiznak Charles University

PSI 2019/2020  Relativity (Kubiznak)  Lecture 3
David Kubiznak Charles University

PSI 2019/2020  Relativity (Kubiznak)  Lecture 4
David Kubiznak Charles University

PSI 2019/2020  Relativity (Kubiznak)  Lecture 5
David Kubiznak Charles University

PSI 2019/2020  Relativity (Kubiznak)  Lecture 6
David Kubiznak Charles University

PSI 2019/2020  Relativity (Kubiznak)  Lecture 7
David Kubiznak Charles University

PSI 2019/2020  Relativity (Kubiznak)  Lecture 8
David Kubiznak Charles University


PSI 2019/2020  Classical Physics (Kubiznak)
8 talksCollection Number C19032Talk

Dynamics and Black Hole Imaging
Collection Number C19051 
PSI 2018/2019  Strong Field Gravity (East)
15 talksCollection Number C19008Talk

PSI 2018/2019  Strong Field Gravity  Lecture 1
William East Perimeter Institute for Theoretical Physics

PSI 2018/2019  Strong Field Gravity  Lecture 2
William East Perimeter Institute for Theoretical Physics


PSI 2018/2019  Strong Field Gravity  Lecture 4
William East Perimeter Institute for Theoretical Physics

PSI 2018/2019  Strong Field Gravity  Lecture 5
William East Perimeter Institute for Theoretical Physics

PSI 2018/2019  Strong Field Gravity  Lecture 6
Luis Lehner Perimeter Institute for Theoretical Physics

PSI 2018/2019  Strong Field Gravity  Lecture 7
William East Perimeter Institute for Theoretical Physics

PSI 2018/2019  Strong Field Gravity  Lecture 8
William East Perimeter Institute for Theoretical Physics


Path to Kilohertz GravitationalWave Astronomy
17 talksCollection Number C18014Talk


Hitting the High Notes: The High Frequency Dynamics of Neutron Star Mergers
William East Perimeter Institute for Theoretical Physics
PIRSA:18060045 
PostMerger Gravitational Wave Emission
Andreas Bauswein Max Planck Institute for Astrophysics (MPA), Garching
PIRSA:18060046 
Searching for Ultralight Particles with Gravitational Waves
Masha Baryakhtar University of Washington
PIRSA:18060047 
3G Detectors, Voyager
Rana Adhikari California Institute of Technology (Caltech)  Division of Physics Mathematics & Astronomy
PIRSA:18060048 

Gravitational Wave Telescopes: Some Cosmological Considerations
Latham Boyle University of Edinburgh
PIRSA:18060050 
Astrophysics and Cosmology with GravitationalWave Population Inference
Eric Thrane Monash University  Department of Physics
PIRSA:18060051


Searching for New Particles with Black Hole Superradiance
11 talksCollection Number C18010Talk

Searching for Light Bosons with Black Hole Superradiance
Savas Dimopoulos Perimeter Institute for Theoretical Physics

Superradiant instabilities and rotating black holes
Sam Dolan University of Southampton
PIRSA:18050028 
Superradiant instabilities and rotating black holes
Avery Broderick University of Waterloo

Measuring StellarMass Black Hole Spins via Xray Spectroscopy
James Steiner Massachusetts Institute of Technology (MIT)

Superradiance Beyond the Linear Regime
Frans Pretorius Princeton University

Characterization of compact objects with present and future groundbased gravitationalwave detectors
Salvatore Vitale Massachusetts Institute of Technology (MIT)

LIGO and Virgo continuous wave searches  Overview and allsky searches
keith Riles University of Michigan–Ann Arbor

Directed and targeted searches for continuous gravitational waves
Sylvia Zhu Albert Einstein Institute


Computational Methods for General Relativistic Magnetohydrodynamics: con2prim an
Collection Number C18001

Gravitational Physics
Collection Number C24007The Gravitational Physics course takes your knowledge and practice of gravity to the next level. We start by recapping the essential elements of differential geometry, adding some new techniques to the toolbox, then apply some of these methods to learning about submanifolds, extra dimensions, and black hole thermodynamics. Towards the end of the course, we delve into the frontiers, with a sample of recent research topics.

Puzzles in the Quantum Gravity Landscape: viewpoints from different approaches
34 talksCollection Number C23033Unraveling the quantum nature of gravity is one of the most pressing problems of theoretical physics. Several ideas have been put forward and resulted in a number of theories of quantum gravity. While these theories have explored different facets of the “quantum gravity landscape”, all viable approaches should ultimately make contact with observations, and answer exciting questions in cosmology and blackhole physics.
Sharing knowledge, exchanging ideas, and building a dictionary between different theories are crucial steps toward answering these questions, efficiently contrasting different theories, and ultimately reaching a deeper understanding of our Universe.
This conference will contribute to these goals by bringing together leading experts in different approaches to quantum gravity, gravitational effective field theory, blackhole physics, and cosmology. We will focus on specific puzzles in quantum gravity and their resolutions within different approaches. The conference will be highly interactive, with plenty of time to discuss common problems, understand the big picture, and develop novel connections between fields.Registration: Registration is now open, and both inperson and virtual participation is welcome. Online participants will be able to interact on an equal footing in question sessions and discussions. Inperson attendance is limited and will be approved on a firstcome, firstserved basis. Talks are by invitation only, but inperson participants are encouraged to apply to present a poster.
Spam warning: There is an increasing number of scam agencies reaching out to conference speakers and attendees. Perimeter Institute does not use thirdparty agencies. We advise speakers and attendees to ignore emails and not to provide any details to anyone who is not from Perimeter Institute.
Confirmed Speakers and Panelists:
 Abhay Ashtekar (Penn State University)
 Robert Brandenberger (McGill University)
 Luca Buoninfante (Nordita)
 Xavier Calmet (University of Sussex)
 Francesco di Filippo (Kyoto University)
 Bianca Dittrich (Perimeter Institute)
 John Donoghue (University of Massachusetts)
 Astrid Eichhorn (CP3origins)
 Johanna Erdmenger (Würzburg University)
 Ghazal Geshnizjani (Perimeter Institute)
 Ruth Gregory (King's College)
 Lavinia Heisenberg (Heidelberg University)
 Bob Holdom (University of Toronto)
 Benjamin Knorr (Nordita)
 Renate Loll (Radboud University Nijmegen)
 Miguel Montero (IFT Madrid)
 Rob Myers (Perimeter Institute)
 Sabrina Pasterski (Perimeter Institute)
 Fernando Quevedo (Cambridge University)
 Lisa Randall (Harvard University)
 Kasia Rejzner (York University)
 Mairi Sakellariadou (King's College)
 Lee Smolin (Perimeter Institute)
 Kellogg Stelle (Imperial College)
 Sumati Surya (Raman Research Institute)
 Andrew Tolley (Imperial College)
 Neil Turok (University of Edinburgh)
 Pedro Vieira (Perimeter Institute)
 Yasaman Yazdi (Imperial College)
Territorial Land Acknowledgement
Perimeter Institute acknowledges that it is situated on the traditional territory of the Anishinaabe, Haudenosaunee, and Neutral peoples.
Perimeter Institute is located on the Haldimand Tract. After the American Revolution, the tract was granted by the British to the Six Nations of the Grand River and the Mississaugas of the Credit First Nation as compensation for their role in the war and for the loss of their traditional lands in upstate New York. Of the 950,000 acres granted to the Haudenosaunee, less than 5 percent remains Six Nations land. Only 6,100 acres remain Mississaugas of the Credit land.
We thank the Anishinaabe, Haudenosaunee, and Neutral peoples for hosting us on their land.

Quantum Simulators of Fundamental Physics
23 talksCollection Number C23019This meeting will bring together researchers from the quantum technology, atomic physics, and fundamental physics communities to discuss how quantum simulation can be used to gain new insight into the physics of black holes and the early Universe. The core program of the workshop is intended to deepen collaboration between the UKbased Quantum Simulators for Fundamental Physics (QSimFP; https://www.qsimfp.org) consortium and researchers at Perimeter Institute and neighbouring institutions. The weeklong conference will consist of broadlyaccessible talks on work within the consortium and work within the broader community of researchers interested in quantum simulation, as well as a poster session and ample time for discussion and collaboration
Territorial Land AcknowledgementPerimeter Institute acknowledges that it is situated on the traditional territory of the Anishinaabe, Haudenosaunee, and Neutral peoples.
Perimeter Institute is located on the Haldimand Tract. After the American Revolution, the tract was granted by the British to the Six Nations of the Grand River and the Mississaugas of the Credit First Nation as compensation for their role in the war and for the loss of their traditional lands in upstate New York. Of the 950,000 acres granted to the Haudenosaunee, less than 5 percent remains Six Nations land. Only 6,100 acres remain Mississaugas of the Credit land.
We thank the Anishinaabe, Haudenosaunee, and Neutral peoples for hosting us on their land.

Gravitational Waves Beyond the Boxes II
15 talksCollection Number C22013Gravitational Waves Beyond the Boxes II 
PSI 2019/2020  Gravitational Physics
15 talksCollection Number C20004PSI 2019/2020  Gravitational Physics 
PSI 2019/2020  Relativity (Kubiznak)
15 talksCollection Number C19039PSI 2019/2020  Relativity (Kubiznak) 
PSI 2019/2020  Classical Physics (Kubiznak)
8 talksCollection Number C19032PSI 2019/2020  Classical Physics (Kubiznak) 
Dynamics and Black Hole Imaging
Collection Number C19051With the advent of black hole imaging, we are now moving forward to black hole cinema. This workshop aims to collect the expertise across the Event Horizon Telescope Collaboration to develop, implement and apply methods to access and interpret variability in M87 and Sgr A*. The goal is to lay the foundation for the first publications based on black hole movies.

PSI 2018/2019  Strong Field Gravity (East)
15 talksCollection Number C19008PSI 2018/2019  Strong Field Gravity (East) 
Path to Kilohertz GravitationalWave Astronomy
17 talksCollection Number C18014We are entering an exponentially growing phase of gravitationalwave (GW) astronomy excitingly represented by the Nobel Prize in Physics last year  only two years after the first detection. The successful multimessenger detection of binary neutron star merger in last August has triggered increasing interests to probe the neutron star postmerger gravitational radiations as they will give more decisive and informative description of the postmerger object itself and the GW/electromagnetic emission mechanism. As the postmerger GWs mainly lie in the 1kHz4kHz band it becomes necessary and important to think about possible thirdgeneration GW detectors that are primarily sensitive to the high frequency band.Â In this workshop we shall focus on possible science case and detector configuration for kHz highfrequency detectors. We will have several invited talks while leaving more time for free discussions. We hope this workshop can serve as a seed for much broader discussions in the GW astronomy community and help promote high frequency detectors as one of the development directions of thirdgeneration GW detectors.

Searching for New Particles with Black Hole Superradiance
11 talksCollection Number C18010Black hole superradiance is a fascinating process in general relativity and a unique window on ultralight particles beyond the standard model. Bosons  such as axions and dark photons  with Compton wavelengths comparable to size of astrophysical black holes grow exponentially to form large clouds spinning down the black hole in the process and produce monochromatic continuous gravitational wave radiation. In the era of gravitational wave astronomy and increasingly sensitive observations of astrophysical black holes and their properties superradiance of new light particles is a promising avenue to search for new physics in regimes inaccessible to terrestrial experiments. This workshop will bring together theorists data analysts and observers in particle physics gravitational wave astronomy strong gravity and high energy astrophysics to explore the signatures of black hole superradiance and to study the current and future possibilities of searching for new particles with black holes.

Computational Methods for General Relativistic Magnetohydrodynamics: con2prim an
Collection Number C18001Computational Methods for General Relativistic Magnetohydrodynamics are important means of studying compact astrophysical objects such as neutron stars and corecollapse supernovae relevant e.g. to understand sources of gravitational radiation.Particular crucial elements of such methods including solving nonlinear equations to extract the microphysical state from the conserved fluxes (endearingly called con2prim) or handling realistic equations of state (EOS) that are only given approximately in a tabulated manner. The state of the art for algorithms addressing these issue leaves to be desired and significantly limits stabilityaccuracy and performance of todays calculations.This workshop aims to review the known algorithmic and computational shortcomings list requirements that an ideal solution should haveand discuss potential practical solutions.