Motion of test particles around an Einstein-dilaton-Gauss-Bonnet black hole in a uniform magnetic field

TL;DR

This paper investigates the motion of magnetized particles around Einstein-dilaton-Gauss-Bonnet black holes in a magnetic field, revealing how coupling parameters influence stable orbit regions through numerical and analytical methods.

Contribution

It introduces a detailed analysis of stable circular orbits around Einstein-dilaton-Gauss-Bonnet black holes in magnetic fields, highlighting the effects of coupling parameters and providing numerical and analytical insights.

Findings

Magnetic interaction creates stable orbit regions near the photonic sphere.

Regions with no circular orbits appear before marginal stability for weak magnetic fields.

Increasing the dilaton-Gauss-Bonnet coupling reduces stable orbit regions.

Abstract

In this work, we study the motion of a magnetized particle orbiting a static and spherically symmetric black hole immersed in an external asymptotically uniform magnetic field in Einstein-dilaton-Gauss-Bonnet gravity. Similar to the Schwarzschild case, the magnetic interaction creates a region that allows circular stable orbits near the photonic sphere, however, we show that regions in which there are no allowed solutions for circular orbits appear before the marginal stability was reached for weak magnetic interaction. The regions of allowed stable circular orbits were calculated for different values of the dilaton-Gauss-Bonnet coupling $p$ and magnetic coupling parameter $\beta$, concluding that the increase of $p$ reduces the regions of stable circular orbits. The calculations were carried out using numerical black hole solutions and were compared with an analytical approximation with an error below $5\%$ for $p<0.25$.