2019/07/03 by Oindrila Ganguly, Ganguly, Oindrila
Engineering · Physics and Astronomy · #Aerodynamics and Acoustics in Jet Flows #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Quantum Electrodynamics and Casimir Effect
paper · pdf · doi:10.48550/arxiv.1907.01905
openalex publication_date 2019/07/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Our knowledge of dynamical black holes suffers from a lack of observational\ninsight. In an analogue model of gravity, we can design a longitudinally\nsymmetric dynamical acoustic black hole with a moving horizon. In this\nsymmetric spacetime, the marginally outer trapped surface and the so called\nevolving horizon are degenerate. Interestingly, there are many ways of\nassigning a surface gravity to the horizon in the absence of time translation\ninvariance. Here, we present two of them that are distinguished by whether they\nare defined only locally or take into account the global properties of\nspacetime outside the black hole. It is expected that a dynamical black hole\nwould emit spontaneous thermal radiation and its temperature would be\nproportional to a surface gravity of the moving horizon but there is no\nconsensus on which of the surface gravities would give the Hawking temperature.\nWe propose that a non-stationary analogue spacetime when realised\nexperimentally can possibly help resolve these mysteries and provide the first\nobservational signatures of dynamical Hawking radiation.\n