Quantum Gravity and Cosmology

Event Date:
2024-10-17T16:00:00
2024-10-17T17:00:00
Event Location:
HENN 201
Speaker:
Dr. Mark van Raamsdonk, University of British Columbia
Related Upcoming Events:
Department Colloquia
Intended Audience:
Everyone
Local Contact:

Georg Rieger (rieger@phas.ubc.ca) and Brett Gladman (gladman@astro.ubc.ca)

*All are welcome to this in-person event!

Event Information:

Abstract: 
In this talk, I'll review how in our current best understanding of quantum gravity (known as holography), classical spacetime and Einstein's equations emerge from intrinsically quantum phenomena such as entanglement. I'll discuss recent efforts to describe cosmological physics (the physics of expanding universes with a big bang) using this approach.  I will explain that while the holographic gravity theories are naively unrealistic because they have a negative cosmological constant, generic cosmological solutions in these models have time-dependent scalar fields that can lead to realistic cosmological evolution with late time accelerated expansion. Observationally, these models can be distinguished from the Lambda-CDM model by the presence of decreasing dark energy. I present an observational study (with Chris Waddell) using supernova and BAO data that suggests such models with decreasing dark energy via a time-dependent scalar are preferred over the standard Lamdba-CDM model in a standard likelihood analysis. The talk will be broadly accessible to undergraduates,  graduate students, and faculty in all fields.

 

Bio:

I am a professor in the Department of Physics and Astronomy at the University of British Columbia, where I have worked since 2002. Before that, I was a postdoc at Stanford University from 2000 until 2002. I studied as a graduate student at Princeton University from 1995 until 2000 when I received my PhD. My supervisor was Washington Taylor. Before that, I did a combined math/physics undergraduate degree at UBC.

I am currently a Simons Investigator and a member of the Simons Foundation "It From Qubit" Collaboration.

In my research, I work towards a better theoretical understanding of elementary particle physics, classical and quantum gravity, and cosmology. Most of my research has focused on string theory, quantum field theory, and the remarkable equivalence between the two suggested by gauge theory/ gravity duality (a.k.a. the AdS/CFT correspondence). Currently, I am exploring connections between quantum information theory and quantum gravity.

 

Awards:

 

Learn More:

Add to Calendar 2024-10-17T16:00:00 2024-10-17T17:00:00 Quantum Gravity and Cosmology Event Information: Abstract: In this talk, I'll review how in our current best understanding of quantum gravity (known as holography), classical spacetime and Einstein's equations emerge from intrinsically quantum phenomena such as entanglement. I'll discuss recent efforts to describe cosmological physics (the physics of expanding universes with a big bang) using this approach.  I will explain that while the holographic gravity theories are naively unrealistic because they have a negative cosmological constant, generic cosmological solutions in these models have time-dependent scalar fields that can lead to realistic cosmological evolution with late time accelerated expansion. Observationally, these models can be distinguished from the Lambda-CDM model by the presence of decreasing dark energy. I present an observational study (with Chris Waddell) using supernova and BAO data that suggests such models with decreasing dark energy via a time-dependent scalar are preferred over the standard Lamdba-CDM model in a standard likelihood analysis. The talk will be broadly accessible to undergraduates,  graduate students, and faculty in all fields.   Bio: I am a professor in the Department of Physics and Astronomy at the University of British Columbia, where I have worked since 2002. Before that, I was a postdoc at Stanford University from 2000 until 2002. I studied as a graduate student at Princeton University from 1995 until 2000 when I received my PhD. My supervisor was Washington Taylor. Before that, I did a combined math/physics undergraduate degree at UBC. I am currently a Simons Investigator and a member of the Simons Foundation "It From Qubit" Collaboration. In my research, I work towards a better theoretical understanding of elementary particle physics, classical and quantum gravity, and cosmology. Most of my research has focused on string theory, quantum field theory, and the remarkable equivalence between the two suggested by gauge theory/ gravity duality (a.k.a. the AdS/CFT correspondence). Currently, I am exploring connections between quantum information theory and quantum gravity.   Awards: Fellow of the Royal Society of Canada, 2023: Mark Van Raamsdonk joins Royal society of Canada Fellows Class of 2023 | UBC Physics & Astronomy Killam Teaching Prize: PHAS James Charbonneau and Mark Van Raamsdonk awarded Killam Teaching Prize | UBC Physics & Astronomy, 2021 UBC Killam Faculty Research Award, 2016 Simons Investigator in Physics, 2015-2020 AP/CRM Medal in Theoretical and Mathematical Physics in, 2014   Learn More: See his Department of Physics & Astronomy faculty webpage here: https://phas.ubc.ca/users/mark-van-raamsdonk Browse through his personal research website: https://phas.ubc.ca/~mav/vanraamsdonk.html View his Simon Foundation webpage here: https://www.simonsfoundation.org/people/mark-van-raamsdonk/ Watch his 2023 Royal Society of Canada Fellow interview on Youtube where he talks about his research and the relation between quantum mechanics and gravity: https://www.youtube.com/watch?v=JQ_As78DZOE  Event Location: HENN 201