70 AIM, UMR 7158, CEA/DRF, CNRS, Université Paris Diderot, Irfu/Service d'Astrophysique,
Centre de Saclay, FR-91191 Gif-sur-Yvette, France

I review the development of numerical evolution codes for general relativity based upon the
characteristic initial-value problem. Progress in characteristic evolution is traced from the …

We present numerical solutions of several spacetimes of physical interest, including binary
black hole mergers, in shift-symmetric Einstein-scalar-Gauss-Bonnet (ESGB) gravity, and …

The majority of extensions to general relativity (GR) display mathematical pathologies—
higher derivatives, character change in equations that can be classified within partial …

We study the initial value problem for Lovelock and Horndeski theories of gravity. We show
that the equations of motion of these theories can be written in a form that, at weak coupling …

We show that self-interacting vector field theories exhibit unphysical behavior even when
they are not coupled to any external field. This means any theory featuring such vectors is in …

One of the major obstacles to testing alternative theories of gravity with gravitational-wave
data from merging binaries of compact objects is the formulation of their field equations …

Effective field theory provides a way of parametrizing strong-field deviations from general
relativity that might be observable in the gravitational waves emitted in a black hole merger …

A bstract We consider four-dimensional general relativity with vanishing cosmological
constant defined on a manifold with a boundary. In Lorentzian signature, the timelike …

Throughout the Universe many powerful events are driven by strong gravitational effects that
require general relativity to fully describe them. These include compact binary mergers …