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…
Gödel-symmetric backgrounds and explicit spacetime symmetry breaking
César Riquelme, Carlos M. Reyes, A. F. Santos
Explicit breaking of diffeomorphism symmetry with nondynamical background fields in gravitational theories can lead to inconsistencies between the equations of motion and the under…
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…
Cosmology with explicit and spontaneous background fields
Carlos M. Reyes, César Riquelme, Alex Soto
We study a general class of effective backgrounds that break diffeomorphism invariance and their potential roles in cosmology. Specifically, we examine both explicit and spontaneou…
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…