The characteristic difference between a black hole and other exotic compact objects (ECOs) is the presence of the horizon. The horizon of a classical black hole acts as a one-way membrane. Due to this nature, any perturbation on the black hole must satisfy ingoing boundary conditions at the horizon. For an ECO either the horizon is replaced or modified with a surface with nonzero reflectivity. This results in a modification of the boundary condition of the perturbation around such systems. In this work, we study how tidal heating of an ECO gets modified due to the presence of a reflective surface and what implication it brings for the gravitational wave observations. We argue that the position of the reflective surface, $ϵ\gtrsim {10}^{-5}$, can have an observational impact in extreme mass ratio inspirals. We also discuss a possible degeneracy between $ϵ$ and reflectivity, $|\mathcal{R}{|}^2$, in the context of parameter estimation.

• Received 24 March 2020
• Revised 28 July 2020
• Accepted 31 August 2020
• Corrected 20 October 2021
• Corrected 24 September 2020

DOI:https://doi.org/10.1103/PhysRevD.102.064040