English

Tidal Deformation Bounds and Perturbation Transfer in Bounded Curvature Spacetimes

General Relativity and Quantum Cosmology 2026-04-20 v2

Abstract

We derive two model-independent results for spacetimes with globally bounded tidal fields. These are operational resolution scales of the local-inertial approximation and tidal dynamics; no spacetime discreteness is implied. Given an invariant bound λmaxλbound\lambda_{\max}\le\lambda_{\rm bound} on the electric Riemann eigenvalues EijR0^i0^jE_{ij}\equiv R_{\hat{0}i\hat{0}j} along freely falling worldlines, we prove (i)~a rigorous upper bound on accumulated geodesic deviation through any bounded curvature interior, controlled by τλmax1/2\tau_*\equiv\lambda_{\max}^{-1/2}, and (ii)~the existence of a critical wavenumber kτ1k_*\sim\tau_*^{-1} separating adiabatic from non-adiabatic perturbation transfer through high-curvature epochs, with Bogoliubov coefficients exponentially suppressed for kτ1k\,\tau_*\gg 1. Both results depend only on the tidal bound (and, for mode transfer, on a mild timescale assumption for the curvature-driven effective potential) and are otherwise insensitive to metric details. For preparation, we collect the standard operational consequences of bounded curvature, including the accuracy-dependent local-inertial domain LLI(ε)ελmax1/2L_{\rm LI}(\varepsilon)\sim\sqrt{\varepsilon}\, \lambda_{\max}^{-1/2} and, for conformally flat cores in four dimensions, the benchmark ratio τ/L=241/4\tau_*/L_*=24^{1/4} with LKmax1/4L_*\equiv K_{\max}^{-1/4}. We quantify the robustness of this coefficient under departures from maximal symmetry via the Weyl-to-Kretschmann ratio ϵC\epsilon_C. The general framework is validated numerically in the extremal Hayward geometry.

Keywords

Cite

@article{arxiv.2602.16285,
  title  = {Tidal Deformation Bounds and Perturbation Transfer in Bounded Curvature Spacetimes},
  author = {Martin Drobczyk},
  journal= {arXiv preprint arXiv:2602.16285},
  year   = {2026}
}

Comments

Revised after peer review; submitted to GRG, 17 pages, 4 figures