Dynamics of particles and epicyclic motions around Schwarzschild-de-Sitter black hole in perfect fluid dark matter

TL;DR

This study explores how perfect fluid dark matter influences circular and epicyclic orbits around Schwarzschild-de Sitter black holes, revealing modifications in orbit stability and potential explanations for observed quasi-periodic oscillations.

Contribution

It introduces the effects of perfect fluid dark matter on orbit regions and stability around Schwarzschild-de Sitter black holes, including implications for twin peak QPO phenomena.

Findings

Dark matter shrinks the stable orbit region.

Existence of double matching stable orbits at specific dark matter parameters.

Dark matter's gravitational attraction dominates over cosmological repulsion.

Abstract

In this paper we investigate circular orbits for test particles around Schwarzschild-de Sitter (dS) black hole surrounded by perfect fluid dark matter. We determine the region of circular orbits bounded by innermost and outermost stable circular orbits. We show that the impact of the perfect fluid dark matter shrinks the region where circular orbits can exist as the values of both innermost and outermost stable circular orbits decrease. We find that for specific lower and upper values of dark matter parameter there exist double matching values for inner and outermost stable circular orbits. It turns out that the gravitational attraction due to the dark matter contribution dominates over cosmological repulsion. This gives rise to a remarkable result in the Schwarzschild-dS black hole surrounded by dark matter field in contrast to the Schwarzschild-dS metric. Finally, we study epicyclic motion and its frequencies with their applications to twin peak quasi-periodic oscillations (QPO) for various models. We find corresponding values of the black hole parameters which could best fit and explain the observed twin peak QPO object GRS 1915+109 from microquasars.