20.500.12556/RUL-185528 Bouncing geodesics, black hole singularities, and singularities of thermal correlators Bouncing geodesics have been used as valuable probes of black hole singularities. In the dual boundary theory, the presence of bouncing geodesics is encoded in the analytic structure of correlation functions. Thus, when their existence is related to the presence of a black hole singularity, this presents a practical holographic framework to analyse, diagnose, and classify spacetimes with curvature singularities. To make this intuition precise, we use the Hadamard theory of hyperbolic differential equations to prove that both bulk and boundary retarded propagators diverge whenever two points can be connected by a null geodesic. We clarify why this statement remains valid beyond the geodesic regime (for operators of any dimension) and examine how holographic renormalisation modifies the structure of the dual propagator. We also present a general characterisation of bouncing geodesics and the associated singularities in correlation functions for arbitrary spacetimes. Furthermore, we compare the analytic structure of the correlators in position and momentum space and discuss explicit examples. Finally, we demonstrate the validity and concrete limitations of the bouncing geodesic approach to the study of black hole singularities. In particular, we show an explicit example of a black hole in the self-dual linear axion model, which has a curvature singularity despite the absence of bouncing geodesics. cosmology blak holes gauge-gravity correspondence spacetime singularities thermal field theory kozmologija črne luknje umeritveno-gravitacijska korespondenca gravitacíjska síngularnost teorija polja true false true Angleški jezik Slovenski jezik Članek v reviji 2026-08-07 12:06:13 2026-08-07 12:06:15 2026-08-08 04:08:09 0000-00-00 00:00:00 2026 0 0 32 str. art. no. 22 Vol. 2026 Aug. 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 539.1 1029-8479 10.1007/JHEP08(2026)022 287238147 https://link.springer.com/article/10.1007/JHEP08(2026)022 1 4a79d322-9247-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=244112 JHEP08(2026)022.pdf JHEP08(2026)022.pdf 1 89AD9BA3C216BD51C17D787716BE4902 cccad9080bbcc721e6ea92081bb8cf5dd13685b7208f089dff11badf06f05db0 eaf99f3b-9247-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=244113 Fakulteta za matematiko in fiziko 0 0 0