Nonlinear/non-iterative treatment of EFT-motivated gravity

TL;DR

This paper develops a fully nonlinear approach to study a higher derivative extension of General Relativity, revealing new phenomena and deviations from standard GR in black hole dynamics and scalar field behavior.

Contribution

It introduces a non-perturbative method for constructing initial data and analyzing evolution in a higher derivative gravity theory, overcoming previous mathematical challenges.

Findings

Demonstrates unexpected phenomena in black hole dynamics.

Shows departures from General Relativity in quasi-normal modes.

Provides a fully nonlinear framework for higher derivative gravity.

Abstract

We study a higher derivative extension to General Relativity and present a fully nonlinear/non-perturbative treatment to construct initial data and study its dynamical behavior in spherical symmetry when coupled to a massless scalar field. For initial data, we compare the obtained solutions with those from alternative treatments that rely on a perturbative (or iterative) approach. For the future evolution of such data, we implement a recently introduced approach which addresses mathematical pathologies brought in by the higher derivatives. Our solutions demonstrate the presence of unexpected phenomena -when seen from the lense of General Relativity, as well as departures from General Relativity in the quasi-normal mode behavior of the scalar field scattering off the black hole.