Observable Optical Signatures, Particle Dynamics and Epicyclic Frequencies of Mod(A)Max Black Holes

TL;DR

This paper explores the optical signatures, particle dynamics, and epicyclic frequencies of Mod(A)Max black holes, revealing how geometric parameters affect observable features and orbital properties relevant for astrophysical observations.

Contribution

It provides a detailed analysis of optical signatures, particle orbits, and oscillation frequencies in Mod(A)Max black hole spacetime, highlighting the influence of charge and coupling parameters.

Findings

Black hole shadow size depends on charge and coupling parameter.

ISCO radius varies with geometric parameters.

Epicyclic frequencies are affected by the black hole's charge and Mod(A)Max coupling.

Abstract

In this work, we investigate the observable optical signatures of the Mod(A)Max black hole spacetime. We analyze key optical features, including the photon sphere, black hole shadow, and photon trajectories, and examine how these observables depend on the underlying geometric parameters, such as the electric charge and the Mod(A)Max coupling parameter. We further study the dynamics of neutral test particles in the vicinity of the black hole by deriving the effective potential within the Hamiltonian formalism. Using this potential, we obtain the specific energy and specific angular momentum for test particles on circular orbits of fixed radius, as well as the innermost stable circular orbit (ISCO), and explore how the geometric parameters influence these quantities and the ISCO radius. Finally, we derive the epicyclic (azimuthal, radial, and vertical) frequencies to analyze quasi-periodic oscillations (QPOs) exploring how the geometric parameters influences these and discuss their physical implications.