On the Interaction between Ultralight Bosons and Quantum-Corrected Black Holes

TL;DR

This paper investigates how ultralight boson clouds around quantum-corrected black holes affect gravitational wave emissions, revealing that reflectivity at the horizon can significantly alter energy fluxes depending on specific parameters.

Contribution

It provides a detailed analysis of gravitational wave flux modifications due to superradiant instabilities in ECOs with reflective boundaries, highlighting the importance of reflectivity in near-horizon physics.

Findings

Reflectivity can suppress or enhance GW fluxes by several orders of magnitude for certain parameters.

Modifications to energy flux are negligible when the product of ECO mass and boson mass is less than 0.5.

Reflectivity significantly influences the near-horizon physics of ECOs.

Abstract

Both ultralight dark matter and exploring the quantum nature of black holes are all topics of great interest in gravitational wave astronomy at present. The superradiant instability allows an exotic compact object (ECO) to be surrounded by an ultralight boson cloud, which leads to the emission of gravitational waves and further triggers rich dynamical effects. In this paper, we study the gravitational effects of superradiant instabilities by calculating the energy fluxes of gravitational waves emitted from ultralight scalar dark matter fields by solving the Teukolsky equation in the background of a massive ECO phenomenologically described by a Kerr geometry with a reflective boundary condition at its physical boundary. We find that both the amplitude and phase of the reflectivity will either suppress or enhance the energy flux of GWs by several orders of magnitude if $M\mu \gtrsim 0.5$ where $M$ and $\mu$ are the mass of ECO and boson, respectively. However, the modifications to energy flux are negligible if $M \mu \lesssim 0.5$. Our results suggest that reflectivity will play a significant role in the near-horizon physics of ECO.