Quasinormal Modes and Greybody factors of de Sitter Black holes surrounded by Quintessence in Rastall gravity

TL;DR

This paper investigates the quasinormal modes, greybody factors, and light trajectories of de Sitter Reissner-Nordström black holes surrounded by quintessence in Rastall gravity, revealing how physical parameters influence black hole properties and wave behaviors.

Contribution

It introduces the effects of Rastall gravity and quintessence on black hole quasinormal modes and greybody factors, highlighting non-linear and linear parameter impacts and the potential masking of black hole charges.

Findings

Increased black hole charge raises oscillation frequency and decay rate of GWs.

Greybody factors decrease with increasing black hole parameters.

Rastall gravity influences light trajectories and may conceal black hole charges.

Abstract

In this work, we have studied the quasinormal mode, greybody factors, and absorption cross section of de Sitter Reissner-Nordstr\"om black hole surrounded by quintessence field in Rastall gravity. The violation of energy-momentum conservation has a non-linear effect on the quasinormal modes. With an increase in the black hole charge, both real parts of quasinormal modes i.e. oscillation frequency of ring-down Gravitational Waves (GWs) and damping or decay rate of GWs increase non-linearly. A similar observation is made for the black hole structural parameter also, however in this case the variation is almost linear. The remnant mass of a black hole depends on different physical parameters of a black hole. In the case of greybody factors also, we observed that both parameters have similar impacts. With an increase in these parameters, greybody factors decrease. Moreover, the null geodesics and the impact of Rastall gravity on the light trajectory are also investigated. Our study suggests that the presence of a surrounding quintessence field may shadow the existence of black hole charges in such black hole configurations.