Horizon--orbit scale competition underlying chaos bound violation for spinning particles
Abstract
In this paper, we investigate the chaos bound through the local radial instability of charged spinning test particles on unstable circular orbits in the black-bounce--Kerr--Newman spacetime. Our results show that violation of the bound is governed by the competition between the local orbital-instability scale and the surface gravity scale, with variations of the black hole background and the particle dynamics providing two complementary routes to the same threshold crossing. Background variations affect both scales and can drive the system into the bound-violating regime when the surface gravity is suppressed more strongly than the orbital instability. At fixed background, by contrast, the surface gravity remains unchanged, and the transition across the threshold is driven by changes in the unstable orbit dynamics induced by the particle parameters. The background-controlled and probe-dynamics-controlled routes therefore represent two realizations of a unified horizon--orbit scale competition rather than independent mechanisms.
Related
- Chaos bound for spinning particles in Kerr-Newman-AdS black holes
- Chaos bound for spinning particles in Kerr-Newman-AdS black holes
- Dynamics of spinning test particles in the innermost stable circular orbit of an approximate Kerr-like spacetime with mass quadrupole
- Magnetically charged spinning particles around a regular black hole: constraints on the monopole charge from quasi-periodic oscillations
- Analytic motions of spinning particles in Schwarzschild-(anti-)de Sitter spacetime
BibTeX
@misc{chen2026horizonorbit,
title = {{Horizon--orbit scale competition underlying chaos bound violation for spinning particles}},
author = {Deyou Chen and Lifang Li and Chuang Yang and Kangqiao Liu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.18143},
eprint = {2609.18143},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.18143},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Horizon--orbit scale competition underlying chaos bound violation for spinning particles
AU - Deyou Chen
AU - Lifang Li
AU - Chuang Yang
AU - Kangqiao Liu
PY - 2026
DA - 2026/09/20
PB - arXiv
DO - 10.48550/arxiv.2609.18143
UR - https://arxiv.org/abs/2609.18143
AB - In this paper, we investigate the chaos bound through the local radial instability of charged spinning test particles on unstable circular orbits in the black-bounce--Kerr--Newman spacetime. Our results show that violation of the bound is governed by the competition between the local orbital-instability scale and the surface gravity scale, with variations of the black hole background and the particle dynamics providing two complementary routes to the same threshold crossing. Background variations affect both scales and can drive the system into the bound-violating regime when the surface gravity is suppressed more strongly than the orbital instability. At fixed background, by contrast, the surface gravity remains unchanged, and the transition across the threshold is driven by changes in the unstable orbit dynamics induced by the particle parameters. The background-controlled and probe-dynamics-controlled routes therefore represent two realizations of a unified horizon--orbit scale competition rather than independent mechanisms.
ER -