Doctoral Defense in Physics - Vyshnav Mohan

Link on Zoom:
https://eu01web.zoom.us/j/68070331503

Doctoral candidate:
Vyshnav Mohan

Title of thesis:
Holographic models of emergent spacetime

Opponents:
Dr. Johanna Erdmenger, Professor at the Faculty of Physics and Astronomy, University of Würzburg, Germany
Dr. Vijay Balasubramanian, Professor at the Department of Physics and Astronomy, University of Pennsylvania, United States

Advisor:
Dr. Lárus Thorlacius, Professor at the Faculty of Physical Sciences, University of Iceland (Main Supervisor)

Other members of the doctoral committee:
Dr. David Lowe, Professor at the Department of Physics, Brown University, Rhode Island, USA
Dr. Friðrik Freyr Gautason, Lecturer at the School of Mathematical Sciences, University of Southampton, UK
Dr. Valentina Giangreco M. Puletti, Professor at the Faculty of Physical Sciences, University of Iceland
Dr. Watse Sybesma, Assistant Professor at the Nordic Institute for Theoretical Physics, Stockholm, Sweden

Chair of Ceremony:
Dr. Birgir Hrafnkelsson, Professor and Head of the Faculty of Physical Sciences, University of Iceland

Abstract:
Black holes are exceptional laboratories where the apparent incompatibility between gravity and quantum mechanics can be sharpened. In this thesis, quantum features of black holes are probed using the holographic principle, with tools from quantum information and algebraic quantum field theory. Operator algebras provide a natural framework for studying gravity as an emergent phenomenon, and we identify sufficient conditions for the emergence of gravitational dynamics. Going in the opposite direction, quantum gravity effects in an eternal black hole can be modelled by adding certain non-perturbative quantum corrections to its semiclassical operator algebra. This leads to an approximate type I von Neumann algebra whose dimension is equal to the exponential of the Bekenstein-Hawking entropy with logarithmic corrections. Non-perturbative corrections also lead to the late-time saturation of holographic complexity, defined as the volume of a codimension-one extremal surface passing through the black hole interior. A second law associated with this complexity is used to establish a black hole singularity theorem. Non-perturbative corrections may become important during gravitational collapse. Black shells, which have been proposed as an alternative endpoint of collapse in string theory, are studied from a thermodynamic perspective and shown to be thermodynamically favoured over black holes for a range of temperatures.

About the doctoral candidate:
Vyshnav Mohan is from Mannar, Kerala, India, where he completed his schooling. He obtained his Bachelor of Science (Research) and Master of Science in Physics from the Indian Institute of Science in Bengaluru. In 2022, he began his PhD at the University of Iceland. When not doing physics, fueled by excessive amounts of caffeine, Vyshnav spends his time sleeping, playing the violin, and offering unsolicited critiques of movies and TV shows.