Charged string loops in Reissner-Nordstr\"{o}m black hole background

TL;DR

This paper investigates the dynamics of charged string loops around Reissner-Nordström black holes, analyzing their motion, oscillations, and potential for explaining observed quasi-periodic oscillations in microquasars.

Contribution

It introduces a new electromagnetic interaction in charged string loop models, explores their trajectories and oscillations, and compares the results with astrophysical observations.

Findings

Charged string loops exhibit complex trajectories influenced by electromagnetic interactions.

Oscillation frequencies of string loops match observed quasi-periodic oscillations in microquasars.

String loops can be ejected from black hole neighborhoods due to electromagnetic forces.

Abstract

We study the motion of current carrying charged string loops in the Reissner-Nordstr\"{o}m black hole background combining the gravitational and electromagnetic field. Introducing new electromagnetic interaction between central charge and charged string loop makes the string loop equations of motion to be non-integrable even in the flat spacetime limit, but it can be governed by an effective potential even in the black hole background. We classify different types of the string loop trajectories using effective potential approach, and we compare the innermost stable string loop positions with loci of the charged particle innermost stable orbits. We examine string loop small oscillations around minima of the string loop effective potential, and we plot radial profiles of the string loop oscillation frequencies for both the radial and vertical modes. We construct charged string loop quasi-periodic oscillations model and we compare it with observed data from microquasars GRO 1655-40, XTE 1550-564, and GRS 1915+105. We also study the acceleration of current carrying string loops along the vertical axis and the string loop ejection from RN black hole neighbourhood, taking also into account the electromagnetic interaction.