3 papers
gr-qc2025
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…
gr-qc2024
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…
gr-qc2024
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…