Quantum chaotic systems and black holes: puzzles and lessons from an information-theoretic perspective

Event Date:
2025-06-05T11:00:00
2025-06-05T12:00:00
Event Location:
HENN 318
Speaker:
Dr. Shreya Vardhan, Caltech
URL:
Zoom (see meeting info, below)
Related Upcoming Events:
Other Talks
Intended Audience:
Everyone
Local Contact:

Jeremy Heyl (heyl@phas.ubc.ca)

All are welcome to join this talk!

Join Zoom Meeting:
https://ubc.zoom.us/j/63422199875?pwd=cCFuka3YRqX0MaOGixOkrMlpAjXavK.1

Meeting ID: 634 2219 9875
Passcode: 052121

Event Information:

Abstract:

Most systems in nature are chaotic many-body systems, and show the universal phenomenon of thermalization. While some "coarse-grained" aspects of thermalization are familiar from our everyday lives, quantum information theory provides a window into more fine-grained universal properties of thermalizing systems. I will discuss examples from my work of insights and surprises that come from asking operationally motivated questions about quantum chaotic systems. I will also introduce approaches for addressing the elusive question of how and why universality emerges across systems with widely differing microscopic dynamics. Remarkably, there is a lot of evidence that black holes in their fundamental description can be seen as examples of highly chaotic quantum many-body systems. While this principle allows us to make predictions for black holes based on properties of quantum chaotic systems, such predictions are often in conflict with the semiclassical description of gravity in a regime where it should naively be valid. I will discuss a proposal for using computational complexity to understand the subtle relation between the semiclassical and fundamental descriptions of the black hole interior.  


Bio:

Shreya Vardhan is a postdoctoral fellow at the Institute for Quantum Information and Matter at Caltech. She received her Ph.D. at MIT in 2022, and was a postdoc at the Stanford Institute for Theoretical Physics from 2022 to April 2025. Shreya's research interests lie at the intersection of quantum information theory, quantum many-body physics, and quantum gravity. Her work has included topics in entanglement dynamics, the black hole information loss paradox, hydrodynamics, and information-theoretic properties of states in conformal field theories. One of her key goals in the next few years will be to better understand the interplay between the dynamics of information and the flow of energy and other conserved quantities in many-body systems. Another important goal will be to test and develop recent ideas about the role of complexity in black hole physics in the context of more realistic gravity models.

Learn More:

Add to Calendar 2025-06-05T11:00:00 2025-06-05T12:00:00 Quantum chaotic systems and black holes: puzzles and lessons from an information-theoretic perspective Event Information: Abstract: Most systems in nature are chaotic many-body systems, and show the universal phenomenon of thermalization. While some "coarse-grained" aspects of thermalization are familiar from our everyday lives, quantum information theory provides a window into more fine-grained universal properties of thermalizing systems. I will discuss examples from my work of insights and surprises that come from asking operationally motivated questions about quantum chaotic systems. I will also introduce approaches for addressing the elusive question of how and why universality emerges across systems with widely differing microscopic dynamics. Remarkably, there is a lot of evidence that black holes in their fundamental description can be seen as examples of highly chaotic quantum many-body systems. While this principle allows us to make predictions for black holes based on properties of quantum chaotic systems, such predictions are often in conflict with the semiclassical description of gravity in a regime where it should naively be valid. I will discuss a proposal for using computational complexity to understand the subtle relation between the semiclassical and fundamental descriptions of the black hole interior.   Bio: Shreya Vardhan is a postdoctoral fellow at the Institute for Quantum Information and Matter at Caltech. She received her Ph.D. at MIT in 2022, and was a postdoc at the Stanford Institute for Theoretical Physics from 2022 to April 2025. Shreya's research interests lie at the intersection of quantum information theory, quantum many-body physics, and quantum gravity. Her work has included topics in entanglement dynamics, the black hole information loss paradox, hydrodynamics, and information-theoretic properties of states in conformal field theories. One of her key goals in the next few years will be to better understand the interplay between the dynamics of information and the flow of energy and other conserved quantities in many-body systems. Another important goal will be to test and develop recent ideas about the role of complexity in black hole physics in the context of more realistic gravity models. Learn More: Watch her videos (there are more on Youtube): BHI Colloquium Talks | 11.18.2024 | Shreya Vardhan (Stanford University): https://www.youtube.com/watch?v=uo8OmGoz8VY Shreya Vardhan (Stanford University): Entanglement dynamics from universal low-lying modes: https://www.youtube.com/watch?v=kYHd7MWatiY Mixed-state entanglement and information recovery in evaporating black holes: https://www.youtube.com/watch?v=ItevkmLw7rE Read her thesis: Chaos and Thermalization in Quantum Many-Body Systems and Gravity: https://dspace.mit.edu/bitstream/handle/1721.1/150679/vardhan-vardhan-phd-physics-2022-thesis.pdf?sequence=1&isAllowed=y  Event Location: HENN 318