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arXiv · 2609.03278

Tidal forces in the quantum Oppenheimer--Snyder black hole

Anuar Idrissov·Hernando Quevedo
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Abstract

We investigate the tidal forces experienced by massive particles in radial free fall in the quantum Oppenheimer--Snyder black hole, a loop quantum gravity correction to the Schwarzschild geometry that describes the exterior of a bouncing dust ball. Using an orthonormal tetrad adapted to a freely falling observer, we show that the radial and angular components of the tidal tensor reproduce their Schwarzschild counterparts at large distances but reverse sign in the interior. The angular zero remains confined between the Cauchy and event horizons and coincides with the latter only in the extremal limit. A particle released from rest does not reach the center, it stops at a turning point inside the Cauchy horizon, where the ratio of the tidal components is independent of the parameters of the solution and is fixed by the transverse equation of state of the effective source. Solving the geodesic deviation equations for two sets of initial conditions, we find that the radial deviation vector attains its maximum at the minimum of the metric function, exactly for one set of initial conditions and asymptotically for the other, and remains finite throughout, in contrast with the Schwarzschild case, in which it diverges at the singularity. This regularity originates in the bounce rather than in a regular core, and therefore protects timelike radial infall while leaving radial null geodesics unaffected. Examining the full range of the quantum parameter, we find that its sign determines whether the tidal sector possesses any of this structure, while its magnitude determines only whether that structure is hidden: beyond the extremal value the geometry becomes horizonless, and the entire deformation history, bounce included, is exposed to distant observers.

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Anuar Idrissov, Hernando Quevedo. 2026-09-03. Tidal forces in the quantum Oppenheimer--Snyder black hole. https://arxiv.org/abs/2609.03278

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