Quasinormal modes, quasiperiodic oscillations and shadow of rotating regular black holes in non-minimally coupled Einstein-Yang-Mills theory

TL;DR

This study explores the properties of rotating regular black holes in Einstein-Yang-Mills theory, analyzing their shadows, quasinormal modes, and quasiperiodic oscillations, and compares them with observational data to distinguish them from Kerr-Newman black holes.

Contribution

It introduces a new effective metric for rotating EYM black holes and investigates their shadow, QNMs, and QPOs, providing observational constraints and distinguishing features from other black hole models.

Findings

Shadow radius decreases with increasing magnetic charge.

Real part of QNMs increases with magnetic charge.

Rotating EYM black holes can be distinguished from Kerr-Newman black holes by shadow size.

Abstract

In this paper we obtain an effective metric describing a regular and rotating magnetic black hole (BH) solution with a Yang-Mills electromagnetic source in Einstein-Yang-Mills (EYM) theory using the Newman--Janis algorithm via the non-complexification radial coordinate procedure. We then study the BH shadow and the quasinormal modes (QNMs) for massless scalar and electromagnetic fields and the quasiperiodic oscillations (QPOs). To this end, we also study the embedding diagram for the rotating EYM BH. The energy conditions, shadow curvature radius, topology and the dynamical evolution of scalar and electromagnetic perturbations using the time domain integration method are investigated. We show that the shadow radius decreases by increasing the magnetic charge, while the real part of QNMs of scalar and electromagnetic fields increases by increasing the magnetic charge. This result is consistent with the inverse relation between the shadow radius and the real part of QNMs. In addition, we have studied observational constraints on the EYM parameter $\lambda$ via frequency analysis of QPOs and the EHT data of shadow cast by the M87 central black hole. We also find that the decaying rate of the EYM BH is slower than that of the neutral and ends up with a tail. We argue that the rotating EYM black hole can be distinguished from the Kerr-Newman black hole with a magnetic charge based on the difference between the angular diameters of their shadows.