COVID-19 information for PI Residents and Visitors
The purpose of this workshop is to discuss and exchange ideas on the most stimulating recent developments in cosmology and fundamental physics. This year, the workshop will focus on four themes: Next Generation Cosmological Probes, Gravitational Wave Astronomy, Fundamental Strong Gravity, and Theoretical Cosmology. We hope that this workshop encourages new ideas and new collaborations among theorists and observers working in cosmology and gravitation. This workshop is the ninth in a series organized jointly by the International Solvay Institutes, APC (Universite Paris VII, Paris) and the Perimeter Institute (Waterloo, Canada). The previous edition was held in Brussels in July, 2015.
Registration for this workshop is now closed.
Sponsorship for this workshop has been provided by:
- Peter Adshead, University of Illinois at Urbana-Champaign
- Yacine Ali-Haimoud, Johns Hopkins University
- Francois Bouchet, Institut d’Astrophysique de Paris
- Kipp Cannon, Research Center for the Early Universe
- William East, SLAC National Accelerator Laboratory
- Bryan Gaensler, University of Toronto
- Vera Gluscevic, Institute for Advanced Study
- Stephen Green, Perimeter Institute
- Gil Holder, McGill University
- Justin Khoury, University of Pennsylvania
- Jean-Luc Lehners, Max Planck Institute for Gravitational Physics
- Steve Liebling, Long Island University
- Eugene Lim, Kings College London
- Marilena LoVerde, Stony Brook University
- Frans Pretorius, Princeton University
- Leonardo Senatore, SLAC National Accelerator Laboratory
- Jon Sievers, University of KwaZulu-Natal
- Neil Turok, Perimeter Institute
- Nicolas Yunes, Montana State University
- Aaron Zimmerman, Canadian Institute for Theoretical Astrophysics
- Peter Adshead, University of Illinois at Urbana-Champaign
- Yacine Ali-Haimoud, Johns Hopkins University
- Cristian Armendariz-Pincon, St. Lawrence University
- Leon Avery, University of Waterloo
- James Bardeen, University of Washington
- Hossein Bazrafshan Moghaddam, McGill University
- Francois Bouchet, Institut d’Astrophysique de Paris
- Latham Boyle, Perimeter Institute
- Alex Buchel, Perimeter Institute
- Kipp Cannon, Research Center for the Early Universe
- Alan Coley, Dalhousie University
- Marina Cortes, Royal Observatory Edinburgh
- William East, SLAC National Accelerator Laboratory
- Solomon Endlich, Stanford University
- Bryan Gaensler, University of Toronto
- Vera Gluscevic, Institute for Advanced Study
- Stephen Green, Perimeter Institute
- Daniel Guariento, Perimeter Institute
- Kurt Hinterbichler, Perimeter Institute
- Renee Hlozek, University of Toronto
- Gil Holder, McGill University
- Mike Hudson, University of Waterloo
- Matthew Johnson, Perimeter Institute & York University
- Mansour Karami, Perimeter Institute
- Justin Khoury, University of Pennsylvania
- Darsh Kodwani, Canadian Institute for Theoretical Astrophysics
- Peter Komorowski, University of Western Ontario
- Luis Lehner, Perimeter Institute
- Jean-Luc Lehners, Max Planck Institute for Gravitational Physics
Andrew Liddle, Royal Observatory Edinburgh - Steve Liebling, Long Island University
- Eugene Lim, Kings College London
- Marilena LoVerde, Stony Brook University
- Andrei Lupu, Vanier College
- Antonino Marciano, Fudan University
- Evan McDonough, McGill University
- Joel Meyers. University of Texas
- John Moffat, Perimeter Institute
- Moritz Muenchmeyer, Institute d'Astrophysique de Paris
- Ali Nayeri, Chapman University
- Elliot Nelson, Perimeter Institute
- Chiamaka Okoli, Perimeter Institute
- Ue-Li Pen, Canadian Institute for Theoretical Astrophysics
- Ashley Perko, Stanford University
- Frans Pretorius, Princeton University
- Leonardo Senatore, SLAC National Accelerator Laboratory
- Mohamad Shalaby, Perimeter Institute & University of Waterloo
- Yutaka Shikano, Institute for Molecular Science, National Institutes of Natural Sciences
- Jon Sievers, University of KwaZulu-Natal
- Kendrick Smith, Perimeter Institute
- Mark Stuckey, Elizabethtown College
- Alexandra Terrana, Perimeter Institute & York University
- Neil Turok, Perimeter Institute
- Robert Van den Hoogen, St. Francis Xavier University
- Alex van Engelen, Canadian Institute for Theoretical Astrophysics
- Nicolas Yunes, Montana State University
- Aaron Zimmerman, Canadian Institute for Theoretical Astrophysics
- Nosiphiwo Zwane, Perimeter Institute
Tuesday, June 14, 2016
Time |
Event |
Location |
9:00 – 9:30am |
Registration |
Reception |
9:30 – 9:40am |
Welcome and Opening Remarks |
Theater |
9:40 – 10:30am |
Yacine Ali-Haimoud, Johns Hopkins University |
Theater |
10:30 – 11:20am |
Coffee Break |
Bistro – 1st Floor |
11:30 – 12:00pm |
Special Announcement |
Theater |
12:00 – 12:50pm |
Justin Khoury, University of Pennsylvania |
Theater |
12:50 – 3:00pm |
Lunch |
Bistro – 2nd Floor |
3:00 – 3:50pm |
Jean-Luc Lehners, Max Planck Institute for Gravitational Physics |
Theater |
3:50pm – 4:40pm |
Leonardo Senatore, SLAC National Accelerator Laboratory |
Theater |
4:40 – 5:30pm |
Vera Gluscevic, Institute for Advanced Study |
Theater |
Wednesday, June 15, 2016
Time |
Event |
Location |
9:30 – 10:20am |
Stephen Green, Perimeter Institute |
Theater |
10:20 – 10:50am |
Coffee Break |
Bistro – 1st Floor |
10:50 – 11:40am |
Aaron Zimmerman, CITA |
Theater |
11:40 – 12:30pm |
Frans Pretorius, Princeton University |
Theater |
12:30 – 12:40pm |
Conference Photo |
TBA |
12:40 – 3:00pm |
Lunch |
Bistro – 2nd Floor |
3:00 – 3:50pm |
Nicolas Yunes, Montana State University |
Theater |
3:50pm – 4:40pm |
Kipp Cannon, Research Center for the Early Universe |
Theater |
5:30pm onwards |
Banquet |
Bistro – 2nd Floor |
Thursday, June 16, 2016
Time |
Event |
Location |
9:30 – 10:20am |
William East, SLAC National Accelerator Laboratory |
Theater |
10:20 – 10:50am |
Coffee Break |
Bistro – 1st Floor |
10:50 – 11:40am |
Eugene Lim, Kings College London |
Theater |
11:40 – 12:30pm |
Steve Liebling, Long Island University |
Theater |
12:30 – 3:00pm |
Lunch |
Bistro – 2nd Floor |
3:00 – 3:50pm |
Francois Bouchet, Institut d’Astrophysique de Paris |
Theater |
3:50pm – 4:40pm |
Gil Holder, McGill University |
Theater |
Friday, June 17, 2016
Time |
Event |
Location |
9:30 – 10:20am |
Peter Adshead, University of Illinois at Urbana-Champaign |
Theater |
10:20 – 10:50am |
Coffee Break |
Bistro – 1st Floor |
10:50 – 11:40am |
Marilena LoVerde, Stony Brook University |
Theater |
11:40 – 12:30pm |
Jon Sievers, University of KwaZulu-Natal |
Theater |
12:30 – 3:00pm |
Lunch |
Bistro – 2nd Floor |
1:00 – 2:00pm |
PI Orchestra Concert |
Atrium |
3:00 – 3:50pm |
Neil Turok, Perimeter Institute |
Theater |
3:50pm – 4:40pm |
Bryan Gaensler, University of Toronto |
Theater |
Peter Adshead, University of Illinois at Urbana-Champaign
Asymmetric reheating and chilly dark sectors
In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model. These theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? I will discuss one possibility, asymmetric reheating, which can populate a thermal dark sector that never reaches thermal equilibrium with the SM.
Yacine Ali-Haimoud, Johns Hopkins University
Dark matter phenomenology across cosmic times
The nature of dark matter remains one of the most nagging problems in cosmology. In this talk I will discuss several existing or potential probes of dark matter. I will start with a well known hot dark matter, massive neutrinos, and discuss their effect on large-scale structure in the non-linear regime. I will then talk about the effect of dark matter interactions with standard model particles on the spectrum of the CMB and on 21cm fluctuations. I will conclude by discussing whether LIGO could have detected primordial-black-hole dark matter.
Francois Bouchet, Institut d’Astrophysique de Paris
Latest cosmological news from the Planck satelitte Project
The Planck collaboration is working towards a "legacy release" by the end of 2016 which will mark the end of the formal collaboration we set up back in the previous century. To this end, we keep improving further our control on the potential level of residual systematics in the data and in accounting for these uncertainties in the final cosmological results to further enhance the robustness and precision of the constraints posed by Planck. For instance, we announced in May an improved likelihood analysis using detailed end-to-end simulation as well as an improved constraint on the reionisation optical depth by using for the first time the E-mode polarisation data from the HFI instrument. This determination fully reconciles the CMB results with other astrophysical measurements of reionization from sources at high redshift. It also gives constraints on the level of reionization at redshifts beyond that of the most distant sources (z > 10). I will further give some perspectives on what is coming next.
William East, SLAC National Accelerator Laboratory
Spacetime Dynamics of the Higgs Instability and the Fate of the Early Universe
A remarkable feature of the Standard Model is that it predicts that, in the absence of new physics, the Higgs field should become unstable at large energies. Though the electroweak vacuum should currently be metastable on timescales that are long compared to the age of the Universe, during an inflationary period, quantum fluctuations could have driven the development of regions of true vacuum at negative energy densities. I will discuss the evolution and spacetime dynamics of unstable Higgs fluctuations, illustrating how they can halt inflation in the regions they develop, and give rise to crunching regions and black holes with unusual properties. By combining this picture from general relativity with a detailed treatment of the stochastic development of such unstable Higgs fluctuations, bounds can be placed on the inflationary energy scale based on the existence of our current Universe.
Bryan Gaensler, University of Toronto
Cosmology and Fundamental Physics with the Square Kilometre Array
The Square Kilometre Array (SKA) is a next-generation radio telescope scheduled to commence construction in 2018. The SKA will be one of a small set of billion-dollar facilities that collectively span the electromagnetic spectrum, and will be an order of magnitude more sensitive than any other radio facility. The SKA's extraordinary survey capacity will allow it to map the distribution of galaxies and large-scale structure over an unprecedented cosmic volume, providing superb probes of dark matter, dark energy, neutrino physics, magnetogenesis, non-gaussianity and inflation. In addition, pulsar timing with the SKA will provide precision tests of general relativity in the strong field regime, and should allow us to detect gravitational radiation produced by merging supermassive black holes. In this talk, I will provide an overview of the capabilities and science goals for the SKA, highlighting its unique potential for advancing our understanding of cosmology and fundamental physics.
Vera Gluscevic, Institute for Advanced Study
A new probe of primordial magnetic fields at high redshift
I will present a novel method for probing extremely weak large-scale magnetic fields in the intergalactic medium prior to the epoch of reionization. This method relies on the effect of spin alignment of hydrogen atoms in a cosmological setting, and on the effect of magnetic precession of the atoms on the statistics of the 21–cm brightness–temperature fluctuations. It is intrinsically sensitive to magnetic fields weaker than 10^{-19} Gauss in physical units, and thus has a potential to reach many orders of magnitude below the current constraints on primordial magnetic fields. I will discuss the physical mechanism, lay out the estimator formalism that enables searches with future 21-cm tomographic surveys, and present forecasts for detecting magnetic fields in the high-redshift universe using this method.
Stephen Green, Perimeter Institute
Turbulent gravity in asymptotically AdS spacetimes
Dynamics in asymptotically anti-de Sitter spacetimes with reflecting boundary conditions are characterized by reduced dissipation as compared to asymptotically flat spacetimes. Such spacetimes, thus, represent opportunities to study nonlinear gravitational interactions that would otherwise be quickly damped away. I will discuss two background spacetimes---large AdS black branes in d=4, and pure AdS---where small perturbations display turbulent behavior and energy cascades driven by nonlinear interactions. In each case, the presence of an unexpected conserved quantity---a gravitational "enstrophy" around the AdS black brane, and a "particle number" for pure AdS perturbations---significantly affects the energy flow direction throughout the cascade, and drives energy to longer distance scales. I will comment on implications for fundamental general relativity questions such as cosmic censorship, and potential for turbulence beyond AdS.
Gil Holder, McGill University
Mapping dark matter on the largest and smallest scales
Using lensing of the CMB we can make maps of the dark matter distribution on the largest cosmological scales, perhaps allowing new insights into gravity, particle physics, and cosmology. With high-resolution maps of distant star-forming galaxies we can map dark matter on small scales within individual galaxies, measuring the small-scale clumping properties of dark matter.
Justin Khoury, University of Pennsylvania
A Dark Matter Superfluid
Jean-Luc Lehners, Max Planck Institute for Gravitational Physics
The Classicality Puzzle
Why was the early universe classical? Along with the big bang singularity problem and the flatness, horizon and inhomogeneity puzzles, this is one of the big unexplained features of the hot big bang scenario. In this talk I will discuss how inflation and ekpyrosis, which have mainly been considered as models that can address some of the other puzzles, can both drive the early universe towards classicality. The remarkable aspect is that classicality is achieved via the intrinsic dynamics of inflation and ekpyrosis, without invoking decoherence.
Steve Liebling, Long Island University
Compact Objects in the Era of GW Astronomy
I will discuss recent work modeling compact objects in an effort to extract scientific understanding from multi-messenger observations.
Eugene Lim, Kings College London
Can inflation really begin with inhomogenous initial conditions?
Marilena LoVerde, Stony Brook University
Structure Formation in a nuCDM Universe
Cosmic background neutrinos are nearly as abundant as cosmic microwave background photons, but their mass, which determines the strength of their gravitational clustering, is unknown. Neutrino oscillation data gives a strict lower limit on neutrino mass, while cosmological datasets provide the most stringent upper limit. Even if the neutrino masses are the minimum required by oscillation data, their gravitational effects on structure formation will nevertheless be detectable in — and in fact required to explain — data within the next decade. I will discuss the physical effects of the cosmic neutrino background on structure formation and present a new signature that may be used to measure neutrino mass with large galaxy surveys.
Frans Pretorius, Princeton University
The Dynamical Strong-field Regime of General Relativity
In this talk I will discuss some of the consequences for our understanding of strong-field gravity that can be gleaned from the recent detection of gravitational waves by the LIGO/Virgo collaboration.
Cosmology and Fundamental Physics with the Square Kilometre Array
The Square Kilometre Array (SKA) is a next-generation radio telescope scheduled to commence construction in 2018. The SKA will be one of a small set of billion-dollar facilities that collectively span the electromagnetic spectrum, and will be an order of magnitude more sensitive than any other radio facility. The SKA's extraordinary survey capacity will allow it to map the distribution of galaxies and large-scale structure over an unprecedented cosmic volume, providing superb probes of dark matter, dark energy, neutrino physics, magnetogenesis, non-gaussianity and inflation.
Shocks in the Early Universe
TBA
Structure Formation in a nuCDM Universe
Cosmic background neutrinos are nearly as abundant as cosmic microwave background photons, but their mass, which determines the strength of their gravitational clustering, is unknown. Neutrino oscillation data gives a strict lower limit on neutrino mass, while cosmological datasets provide the most stringent upper limit. Even if the neutrino masses are the minimum required by oscillation data, their gravitational effects on structure formation will nevertheless be detectable in — and in fact required to explain — data within the next decade.
Asymmetric reheating and chilly dark sectors
In a broad class of theories, the relic abundance of dark matter is determined by interactions internal to a thermalized dark sector, with no direct involvement of the Standard Model. These theories raise an immediate cosmological question: how was the dark sector initially populated in the early universe? I will discuss one possibility, asymmetric reheating, which can populate a thermal dark sector that never reaches thermal equilibrium with the SM.
Mapping dark matter on the largest and smallest scales
Using lensing of the CMB we can make maps of the dark matter distribution on the largest cosmological scales, perhaps allowing new insights into gravity, particle physics, and cosmology. With high-resolution maps of distant star-forming galaxies we can map dark matter on small scales within individual galaxies, measuring the small-scale clumping properties of dark matter.
Latest cosmological news from the Planck satelitte Project
The Planck collaboration is working towards a "legacy release" by the end of 2016 which will mark the end of the formal collaboration we set up back in the previous century. To this end, we keep improving further our control on the potential level of residual systematics in the data and in accounting for these uncertainties in the final cosmological results to further enhance the robustness and precision of the constraints posed by Planck.
Compact Objects in the Era of GW Astronomy
I will discuss recent work modeling compact objects in an effort to extract scientific understanding from multi-messenger observations.
Can inflation really begin with inhomogenous initial conditions?
Spacetime Dynamics of the Higgs Instability and the Fate of the Early Universe
A remarkable feature of the Standard Model is that it predicts that, in the absence of new physics, the Higgs field should become unstable at large energies. Though the electroweak vacuum should currently be metastable on timescales that are long compared to the age of the Universe, during an inflationary period, quantum fluctuations could have driven the development of regions of true vacuum at negative energy densities.
Pages
Scientific Organziers:
- Matthew Johnson, Perimeter Institute & York University
- Kendrick Smith, Perimeter Institute