Superradiance of Charged Static Black Hole in Cubic Gravity

TL;DR

This paper derives an analytical charged black hole solution in higher curvature Einstein-cubic gravity, investigates its thermodynamics, and analyzes superradiance phenomena, showing how black hole charge and mass influence superradiant amplification.

Contribution

It provides the first analytical charged black hole solution in Einstein-cubic gravity and links superradiance effects to black hole thermodynamics in this context.

Findings

Superradiance amplification depends on black hole charge and wave frequency.

Black hole mass and charge decrease during superradiance.

Thermodynamic analysis aligns with field equation solutions.

Abstract

Higher curvature gravity usually has complicated field equations, and solving them analytically is strenuous. In this work, we obtain an analytical charged black hole (BH) solution in higher curvature gravity using the thermodynamics of black holes and employing the continued fraction expansion. We investigate the thermodynamics of static black holes using the first law of thermodynamics and the Smarr formula in their proper form for Einstein-cubic gravity (ECG). Next, we obtain the thermodynamic quantities and show that our results are similar to those from solving the field equations. Then, we study the superradiance of the black hole using massless charged-scalar perturbations. We derive the superradiant conditions and compute the amplification factor through direct integration. We demonstrate how the amplification factor will change as a function of the black hole charge and frequency of the incident wave. We also show that a black hole mass and charge are decreasing in the superradiance region. Finally, we discuss superradiance as a consequence of black hole thermodynamics in ECG.