# Probing Planckian corrections at the horizon scale with LISA binaries

## TL;DR

This paper investigates how future LISA gravitational wave observations could detect Planck-scale quantum-gravity effects at the horizons of supermassive compact objects by analyzing tidal heating and deformability signatures.

## Contribution

It introduces a model-independent approach to probe quantum-gravity corrections at the horizon scale using gravitational wave data from LISA, focusing on tidal effects.

## Key findings

- Tidal heating effects dominate and can constrain Planck-scale corrections.
- Measurement of tidal Love numbers is challenging but can constrain compactness.
- Highly-spinning supermassive binaries offer the best tests of quantum-gravity effects.

## Abstract

Several quantum-gravity models of compact objects predict microscopic or even Planckian corrections at the horizon scale. We explore the possibility of measuring two model-independent, smoking-gun effects of these corrections in the gravitational waveform of a compact binary, namely the absence of tidal heating and the presence of tidal deformability. For events detectable by the future space-based interferometer LISA, we show that the effect of tidal heating dominates and allows one to constrain putative corrections down to the Planck scale. The measurement of the tidal Love numbers with LISA is more challenging but, in optimistic scenarios, it allows to constrain the compactness of a supermassive exotic compact object down to the Planck scale. Our analysis suggests that highly-spinning, supermassive binaries at 1-20 Gpc provide unparalleled tests of quantum-gravity effects at the horizon scale.