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PUG Seminar

PUG Seminar

Whitmore 321 (IGC Lounge)

2025-01-24

In this seminar, we will explore the interplay between quantum mechanics and general relativity by examining the behavior of a quantum clock in curved spacetime. Unlike a classical point mass, a quantum clock with nonzero position fluctuations cannot travel along a single geodesic. Instead, it behaves as an extended object influenced by tidal forces and a superposition of time dilations at different altitudes. Using a geometrical formulation of quantum mechanics, we will show that quantum correlations between spatial directions introduce a non-Riemannian structure to the spacetime experienced by the clock. A specific version of Finsler geometry provides a new setting for a combination of quantum and gravitational effects. The Finsler structure is parameterized by entropy and purity of the state, and uncertainty relations prevent it from being Riemannian. By unifying quantum and gravitational effects in a geometric framework, this approach offers new avenues for advancements in our understanding of quantum reference frames and their applications in semi-classical gravity.

TimeSpeakerTitle
13:45Joey BalsellsRelativistic implications of entropy and purity
About our wordmark
Monica The IGC wordmark was created by Monica Rincon Ramirez, while she was a graduate student at the Institute for Gravitation and the Cosmos (IGC). Monica enjoys drawing new connections between fundamental theory and observations. Her graduate work includes specialized topics in general relativity, loop quantum gravity, and quantum fields in cosmological backgrounds. In particular, her thesis work focused on finding effective quantum corrections to gravitational phenomena from spinfoams, and applications to cosmology. She received her PhD in 2024.

The wordmark symbolizes the scope and variety of research at the IGC. The base of the image represents quantum gravity, evoking the quantum geometrical picture from spinfoams and loop quantum gravity. These are among the approaches to fundamental questions studied at the Center for Fundamental Theory. The middle of the image represents the Center for Theoretical and Observational Cosmology by galaxies embedded in a smooth surface, characteristic of spacetime in general relativity and the much larger physical scales studied in cosmology. Finally, at the top, the surface curves to an extreme, representing a supermassive black hole accompanied by an energetic jet. These elements depict an active galactic nucleus, inspired by Centaurus A. Just to the right, a pair of black holes approaches merger. This top portion of the wordmark represents the Center for Multimessenger Astrophysics, which specializes in the study of high-energy phenomena in the universe.