5 papers
New constraints on modified gravity with dimension-six operators from gravitational waves
Justo López-Sarrión, Carlos M. Reyes, César Riquelme +1
The present article deals with gravitational-wave propagation affected by higher-derivative terms that break spacetime symmetries. Two dimension-6 contributions of the gravitationa…
Vacuum Cherenkov radiation for nonminimal dimension-5 Lorentz violation
A. Yu. Petrov, M. Schreck, A. R. Vieira
Vacuum Cherenkov radiation is investigated in the Lorentz-violating Standard-Model Extension for isotropic dim-5 operators and in the fermion sector. Both the…
Cosmic Backgrounds in the Gravitational Standard-Model Extension
C. M. Reyes, C. Riquelme, M. Schreck +1
We consider background fields within the gravitational sector of the Standard-Model Extension (SME) in a cosmological setting. Our analysis is divided into two parts. The first par…
Hamiltonian formulation for scalar model of spontaneous spacetime symmetry violation in gravity
João Victor V. Santos, Marco Schreck
The focus of this article is on a modification of General Relativity (GR) governed by a dynamical scalar field. The latter is able to acquire a nonzero spacetime-dependent vacuum e…
Reduced geometry and its role in explicit spacetime symmetry violation
Carlos M. Reyes, César Riquelme, Marco Schreck +1
The incompatibility of explicit diffeomorphism violation with Riemannian geometry within the gravitational Standard-Model Extension (SME) is revisited. We review two methods of how…