A little excitement across the horizon

• Main Authors: Ng, Keith K., Zhang, Chen, Louko Jorma, Mann Robert B.
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2023
• Subjects: Science::Physics; Black Hole Radiation; Curved Spacetime Quantum Field
• Online Access: https://hdl.handle.net/10356/170764
• Institution: Nanyang Technological University

We analyse numerically the transitions in an Unruh-DeWitt detector, coupled linearly to a massless scalar field, in radial infall in (3 + 1)-dimensional Schwarzschild spacetime. In the Hartle-Hawking and Unruh states, the transition probability attains a small local extremum near the horizon-crossing and is then moderately enhanced on approaching the singularity. In the Boulware state, the transition probability drops on approaching the horizon. The unexpected near-horizon extremum arises numerically from angular momentum superpositions, with a deeper physical explanation to be found.