Cosmologists at Perimeter Institute seek to help pin down the constituents and history of our universe, and the rules governing its origin and evolution. Many of the most interesting clues about physics beyond the standard model (e.g., dark matter, dark energy, the matter/antimatter asymmetry, and the spectrum of primordial density perturbations], come from cosmological observations, and cosmological observations are often the best way to test or constrain a proposed modification of the laws of nature, since such observations can probe length scales, time scales, and energy scales that are beyond the reach of terrestrial laboratories.
Format results

25 talksCollection Number C19047
Talk

Welcome and Opening Remarks
Bianca Dittrich Perimeter Institute for Theoretical Physics

Quantum Spacetime from Lattice Gravity à la CDT
Renate Loll Radboud Universiteit Nijmegen

How complement maps can cure divergences
Sylvie Paycha University of Potsdam

The gravitational Wilson loop and the nonAbelian Stokes' theorem
Reiko Toriumi Okinawa Institute of Science and Technology Graduate University

The dynamics of difference
Lee Smolin Perimeter Institute for Theoretical Physics


Probing fundamental physics with gravitational waves
Cecilia Chirenti Universidade Federal do ABC

Implications of the Quantum Nature Spacetime for the Big Bang and Black Holes
Abhay Ashtekar Pennsylvania State University


Everpresent Lambda: Theory Meets Observations
15 talksCollection Number C19046Talk


Introduction to Everpresent Lambda
Rafael Sorkin Perimeter Institute for Theoretical Physics

Status of Hubble tension in Cosmology
Niayesh Afshordi University of Waterloo

Causal Set Action/Entropy
Yasaman Kouchekzadeh Yazdi Dublin Institute For Advanced Studies

Observational constraints on modified gravity and dark energy
Jian Li Simon Fraser University (SFU)

Supplementary considerations on Everpresent Lambda
Rafael Sorkin Perimeter Institute for Theoretical Physics


Implementing a stochastic dark energy framework into CAMB
Levon Pogosian Simon Fraser University (SFU)


Simplicity III
17 talksCollection Number C19044Talk

On the possible role of nilpotent internal symmetries in unification
Andras Laszlo Wigner Research Center for Physics

Rethinking the origin of neutrino masses: the role of gravity
Lena Funcke University of Bonn

Swampland Constraints on Neutrino Masses and Dark Energy
Irene Valenzuela Cornell University


Exceptional Quantum Algebra for the Standard Model of Particle Physics
Ivan Todorov Bulgarian Academy of Sciences

SO(7,7) Structure of Standard Model Fermions
Kirill Krasnov University of Nottingham

The Standard Model from A Jordan Algebra
Latham Boyle University of Edinburgh

Particle Theory from Jordan Geometry
Shane Farnsworth Max Planck Institute for Gravitational Physics  Albert Einstein Institute (AEI)


Cosmological Frontiers in Fundamental Physics 2019
22 talksCollection Number C19037Talk

CPTSymmetric Universe
Latham Boyle University of Edinburgh

Brane cosmology and the selftuning of the cosmological constant
Francesco Nitti Université Paris Cité

New Physics in the RayleighJeans tale of the CMB and cosmic 21cm signal
Maxim Pospelov University of Minnesota

Gravitational waves in the inhomogeneous Universe
Masamune Oguri Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU)


Discussion: Where in the Cosmos should we look for novel physics?
Elias Kiritsis University of Crete

Gravitational wave standard sirens
Samaya Nissanke University of Amsterdam

Cosmology and fundamental physics with FRBs
UeLi Pen Canadian Institute for Theoretical Astrophysics (CITA)


PSI 2018/2019  Explorations in Cosmology (Smith)
13 talksCollection Number C19020Talk

PSI 2018/2019  Explorations in Cosmology  Lecture 1
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2018/2019  Explorations in Cosmology  Lecture 2
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2018/2019  Explorations in Cosmology  Lecture 3
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2018/2019  Explorations in Cosmology  Lecture 4
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2018/2019  Explorations in Cosmology  Lecture 5
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2018/2019  Explorations in Cosmology  Lecture 6
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2018/2019  Explorations in Cosmology  Lecture 7
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2018/2019  Explorations in Cosmology  Lecture 8
Kendrick Smith Perimeter Institute for Theoretical Physics


PICITA Day 2019
6 talksCollection Number C19016Talk

Angular momentum radiated by electromagnetic vs gravitational waves
Beatrice Bonga Radboud Universiteit Nijmegen

Ultralight axions and Future CMB experiments
Renee Hlozek University of Toronto

Not extending the standard cosmological model
Andrew Liddle University of Lisbon

The Astrophysics of Cosmic Rays
Tova M. YoastHull Canadian Institute for Theoretical Astrophysics (CITA)

The existence and stability of marginally trapped surfaces
Erik Schnetter Perimeter Institute for Theoretical Physics



PSI 2018/2019  Cosmology Review (Xu)
15 talksCollection Number C19001Talk

PSI 2018/2019  Cosmology Review  Lecture 1
Gang Xu Perimeter Institute for Theoretical Physics

PSI 2018/2019  Cosmology Review  Lecture 2
Gang Xu Perimeter Institute for Theoretical Physics

PSI 2018/2019  Cosmology Review  Lecture 3
Gang Xu Perimeter Institute for Theoretical Physics

PSI 2018/2019  Cosmology Review  Lecture 4
Gang Xu Perimeter Institute for Theoretical Physics

PSI 2018/2019  Cosmology Review  Lecture 5
Gang Xu Perimeter Institute for Theoretical Physics

PSI 2018/2019  Cosmology Review  Lecture 6
Gang Xu Perimeter Institute for Theoretical Physics

PSI 2018/2019  Cosmology Review  Lecture 7
Gang Xu Perimeter Institute for Theoretical Physics

PSI 2018/2019  Cosmology Review  Lecture 8
Gang Xu Perimeter Institute for Theoretical Physics


PSI 2018/2019  Foundations of Quantum Mechanics (Leifer)
15 talksCollection Number C19002Talk

PSI 2018/2019  Foundations of Quantum Mechanics  Lecture 1
Matthew Leifer Chapman University
PIRSA:19010017 
PSI 2018/2019  Foundations of Quantum Mechanics  Lecture 2
Matthew Leifer Chapman University
PIRSA:19010018 
PSI 2018/2019  Foundations of Quantum Mechanics  Lecture 3
Matthew Leifer Chapman University
PIRSA:19010019 
PSI 2018/2019  Foundations of Quantum Mechanics  Lecture 4
Matthew Leifer Chapman University
PIRSA:19010020 
PSI 2018/2019  Foundations of Quantum Mechanics  Lecture 5
Matthew Leifer Chapman University
PIRSA:19010021 
PSI 2018/2019  Foundations of Quantum Mechanics  Lecture 6
Matthew Leifer Chapman University
PIRSA:19010022 
PSI 2018/2019  Foundations of Quantum Mechanics  Lecture 7
Matthew Leifer Chapman University
PIRSA:19010023 
PSI 2018/2019  Foundations of Quantum Mechanics  Lecture 8
Matthew Leifer Chapman University
PIRSA:19010024


Asymptotic Safety in a Dark Universe
17 talksCollection Number C18012Talk

Charting Fundamental Interactions
Francesco Sannino CP3Origins

Asymptotic safety with and without supersymmetry
Daniel Litim University of Sussex


Progress in constructing an Asymptotically safe Standard Model
Steven Abel Durham University

Cosmological nonConstant Problem
Niayesh Afshordi University of Waterloo


UVcomplete relativistic field theories and softened gravity
Alberto Salvio Scuola Normale Superiore di Pisa

Asymptotic safety of gravitymatter systems and effective universality
Manuel Reichert University of Southern Denmark


PSI 2017/2018  Cosmology (Smith)
15 talksCollection Number C17053Talk

PSI 2017/2018  Cosmology  Lecture 1
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2017/2018  Cosmology  Lecture 2
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2017/2018  Cosmology  Lecture 3
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2017/2018  Cosmology  Lecture 4
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2017/2018  Cosmology  Lecture 5
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2017/2018  Cosmology  Lecture 6
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2017/2018  Cosmology  Lecture 7
Kendrick Smith Perimeter Institute for Theoretical Physics

PSI 2017/2018  Cosmology  Lecture 8
Kendrick Smith Perimeter Institute for Theoretical Physics


General Relativity for Cosmology (PHYS786/AMATH875)  Achim Kempf
24 talksCollection Number C17021Talk

General Relativity for Cosmology  Lecture 1
Achim Kempf University of Waterloo

General Relativity for Cosmology  Lecture 2
Achim Kempf University of Waterloo

General Relativity for Cosmology  Lecture 3
Achim Kempf University of Waterloo

General Relativity for Cosmology  Lecture 4
Achim Kempf University of Waterloo

General Relativity for Cosmology  Lecture 5
Achim Kempf University of Waterloo

General Relativity for Cosmology  Lecture 6
Achim Kempf University of Waterloo


General Relativity for Cosmology  Lecture 8
Achim Kempf University of Waterloo


Bounce Scenarios in Cosmology
16 talksCollection Number C17024Talk

Welcome and Opening Remarks

Steffen Gielen University of Sheffield

Neil Turok University of Edinburgh


Bounce in Loop Quantum Cosmology and its Implications
Abhay Ashtekar Pennsylvania State University

Observable Consequences of a Bounce
UeLi Pen Canadian Institute for Theoretical Astrophysics (CITA)

Challenges for Bouncing Cosmologies
Robert Brandenberger McGill University  Department of Physics

Emergent bouncing cosmology from quantum gravity condensates
Edward WilsonEwing University of New Brunswick

Discussion Session 2

Angelika Fertig TotalEnergies (France)

Steffen Gielen University of Sheffield

Elizabeth Gould Arthur B. McDonald Canadian Astroparticle Physics Research Institute





Emmy Noether Workshop: The Structure of Quantum Space Time
25 talksCollection Number C19047Understanding the smallscale structure of spacetime is one of the biggest challenges faced by modern theoretical physics. There are many different attempts to solve this problem and they reflect the diversity of approaches to quantum gravity. This workshop will bring together researchers from a wide range of quantum gravity approaches and give them an opportunity to exchange ideas and gain new insights.

Everpresent Lambda: Theory Meets Observations
15 talksCollection Number C19046One of the biggest mysteries in cosmology and fundamental physics is the nature of dark energy that is responsible for the current acceleration of cosmic expansion. While a cosmological constant provides the simplest model of dark energy recent observational tensions amongst supernovae Ia gravitational lensing time delays and cosmic microwave background suggest the need for a more complex dynamical dark energy. One of the oldest proposals for a dynamical dark energy is Everpresent Lambda proposed by Sorkin which is inspired by the causal set model of quantum gravity. It was recently shown that this model can potentially resolve the tensions in cosmological observations. The meeting aims to bring together a small number of experts in quantum gravity causal sets and cosmology to carefully examine the models theoretical predictions and its observational tests and pave the way for what might be an(other) exciting insight from cosmology into the fundamental nature of spacetime.

Simplicity III
17 talksCollection Number C19044This crossdisciplinary workshop gathers theorists who have been working on novel approaches to understanding the structure of the Standard Model and its link to cosmology and gravity. It follows the previous Simplicity I and II workshops at Princeton University (2014) and Fermilab (2016) and will be a small informal meeting with plenty of room for discussions.

Cosmological Frontiers in Fundamental Physics 2019
22 talksCollection Number C19037The workshops focuses on novel frontiers in observational cosmology and astrophysics and how they shed light fundamental questions in understanding the universe. Registration for this workshop is now open.

PSI 2018/2019  Explorations in Cosmology (Smith)
13 talksCollection Number C19020PSI 2018/2019  Explorations in Cosmology (Smith) 
PICITA Day 2019
6 talksCollection Number C19016This is an ongoing series of meetings held two or three times per year between researchers at Perimeter Institute and CITA. The goal of these meetings is to share new ideas and encourage interaction in PI and CITA's common fields of interest through a series of informal talks followed by discussions.

PSI 2018/2019  Cosmology Review (Xu)
15 talksCollection Number C19001PSI 2018/2019  Cosmology Review (Xu) 
PSI 2018/2019  Foundations of Quantum Mechanics (Leifer)
15 talksCollection Number C19002PSI 2018/2019  Foundations of Quantum Mechanics (Leifer) 
Asymptotic Safety in a Dark Universe
17 talksCollection Number C18012The asymptotic safety paradigm is currently emerging as a highly promising idea for BeyondStandardModel physics with key progress in asymptotically safe quantum gravity and asymptotically safe matter models. The last years have seen not only the development of asymptotically safe gravitymatter models but also the discovery of asymptotically safe beyond Standard Model matter models that are under control in perturbation theory. New exciting avenues in (astro) particle physics are now waiting to be explored. For example although the nature of dark matter is a longstanding riddle it is a fact that experimental searches have so far not provided any direct clues but have instead come up with ever more stringent constraints on theoretically preferred regions of parameter space for darkmattermodels. Thus the key to unraveling this riddle could be a new theoretical paradigm to guide model builders. This workshop aims at exploring whether asymptotic safety can be a candidate for this new paradigm. We aim to bring together experts on phenomenological models and quantum gravity to probe both the theoretical viability and empirical signatures of asymptotically safe extensions of the standard model that include gravity. To facilitate a highly productive meeting that can trigger new collaborations each talk will be followed up by 1520 minutes discussion time. Further each day of the workshop will feature a dedicated discussion session. Participants will be encouraged to contribute questions for the discussion both before as well as during the workshop. The last day of the workshop will conclude with a roadmap discussion during which all participants will be given the opportunity to propose concrete suggestions for followup work that might lead into future joint projects.

PSI 2017/2018  Cosmology (Smith)
15 talksCollection Number C17053PSI 2017/2018  Cosmology (Smith) 
General Relativity for Cosmology (PHYS786/AMATH875)  Achim Kempf
24 talksCollection Number C17021General Relativity for Cosmology (PHYS786/AMATH875)  Achim Kempf 