PhD Comprehensive Exam | Maria Rosa Preciado Rivas, Quantum Detectors Freely Falling into Black Holes

Location

M3 4206

Candidate

Maria Rosa Preciado Rivas | Applied Mathematics, University of Waterloo

Title

Quantum Detectors Freely Falling into Black Holes

Abstract

Since the discovery of the Unruh effect in the 1970s using quantum detectors, efforts have been dedicated to the study of these detectors in curved spacetime because their response encodes information about fluctuations of the vacuum state of a field and, hence, of its underlying spacetime. However, after almost five decades of dedicated research, little is known about the response of quantum detectors as they freely fall into black holes. Here, we present numerical results detailing the response of a detector interacting with the Hartle-Hawking vacuum state of a massless scalar field in a Ba˜nados-Teitelboim-Zanelli (BTZ) black hole as the detector freely falls toward and across the event horizon. We also discuss how this response changes when accounting for the black hole’s rotation and for a different interior topology, as seen in the geon counterpart of the BTZ black hole. Our results suggest that the detector can potentially serve as an ‘early warning system’ that indicates the event horizon’s presence and discerns the black hole’s interior topology. Having established the theoretical and numerical tools to calculate the response of a freely falling detector in BTZ spacetime, we propose considering additional detectors to study entanglement between them when one falls into the black hole. Another proposed research direction is to study a detector in a quantum superposition of trajectories: one in which the detector is outside the event horizon and another where it is inside. We expect that our results will enrich our understanding of detectors freely falling into black holes and provide further insight into the effect of the gravitational field on quantum systems.