# Scattering Amplitudes, Black Holes and Leading Singularities in Cubic Theories of Gravity

## TL;DR

This paper uses modern amplitude techniques to compute the semi-classical potential in cubic gravity theories, revealing non-dispersive terms linked to black hole solutions and demonstrating efficient derivation of classical effects from leading singularities.

## Contribution

It introduces a novel approach to compute potentials in cubic gravity using amplitude methods, connecting non-dispersive terms to black hole solutions and simplifying classical effect calculations.

## Key findings

- Non-dispersive terms lead to black hole solutions with quantum corrections.
- Potential derived matches Einsteinian cubic gravity results.
- Classical effects can be obtained from leading singularities with less computational effort.

## Abstract

We compute the semi-classical potential arising from a generic theory of cubic gravity, a higher derivative theory of spin-2 particles, in the framework of modern amplitude techniques. We show that there are several interesting aspects of the potential, including some non-dispersive terms that lead to black hole solutions (include quantum corrections) that agree with those derived in Einsteinian cubic gravity (ECG). We show that these non-dispersive terms could be obtained from theories that include the Gauss-Bonnet cubic invariant $G_3$. In addition, we derive the one-loop scattering amplitudes using both unitarity cuts and via the leading singularity, showing that the classical effects of higher derivative gravity can be easily obtained directly from the leading singularity with far less computational cost.