Bound on Lyapunov exponent in Einstein-Maxwell-Dilaton-Axion black holes*

Abstract

In this paper, we investigate the influence of the angular momentum of a charged particle around non-extremal and extremal Einstein-Maxwell-Dilaton-Axion black holes on the Lyapunov exponent. The angular momentum's ranges and spatial regions where the bound of the exponent is violated are found for certain values of the rotation parameter and dilatonic constant of the black holes. This violation always exists when the rotation parameter is large enough and the rotation directions of the particle is opposite to those of the black holes. The spatial regions outside the extermal black hole for the violation is relatively large. In the near-horizon regions of the extremal black holes, the violation depends on the rotation directions of the black holes and particle, and does not depend on the value of the angular momentum.Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

Bound on the Lyapunov exponent in Kerr-Newman black holes via a charged particle

“…The bound is associated with the Hawking temperature of the black hole instead of the temperature of the thermal quantum system [26]. The bound has been tested many times by varying the geometry of the spacetime in [27][28][29][30][31][32][33][34][35].…”

Chaos bound in Kerr-Newman-Taub-NUT black holes via circular motions*

“…( 1). There are cases in which the chaos bound is violated [72][73][74][75][76]. The chaos bound has also been studied via the motion of particles near horizons.…”

“…When the angular momentum was considered, the exponent of chaos for charged particles around charged rotating black holes was obtained. The violations of the bound were found in [74,75]. In [50,77,78], two exponents for a rotating BTZ black hole were obtained by calculating out-of-time-order correlators, one of which obeys the bound, whereas the other violates it.…”