Events

Title: Cosmology via holography

Abstract: We describe how the holographic approach to quantum gravity might be used to give a full-fledged quantum gravity description of big-bang cosmology.  In these models, the cosmological observables are related by analytic continuation to the observables in a Euclidean wormhole geometry that is described holographically by a pair of three-dimensional Euclidean conformal field theories. The resulting cosmological models have a negative cosmological constant but can generically explain late-time acceleration due to the potential energy of time-dependent scalar fields associated with relevant scalar operators in the CFT. If such models can describe realistic cosmology, they would predict time-dependent dark energy that decreases and eventually switches sign, leading to a big crunch. We show that such decreasing dark energy is consistent with and perhaps even preferred by scale factor evolution data deduced from the most recent supernova observations.

Bio: Mark Van Raamsdonk is a professor of in the Department of Physics and Astronomy at the University of British Columbia. He received his PhD in theoretical physics from Princeton University before undertaking postdoctoral research at Stanford University. His research focuses on quantum gravity and its connections to quantum information theory and to cosmology. Since 2009, he has explored connections between quantum gravity and quantum information theory, helping to describe how spacetime geometry and gravitational dynamics can emerge from the structure and evolution of quantum entanglement in holographic models of gravity.

Monday, November 13, 2023 11:00 AM - 12:00 PM