3 papers
gr-qc2024
Gravitational and electromagnetic Cherenkov radiation constraints in modified dispersion relations
Mikel Artola, José A. R. Cembranos, Prado Martín-Moruno
Motivated by different approaches to quantum gravity, one could consider that Lorentz invariance is not an exact symmetry of nature at all energy scales. Following this spirit, mod…
gr-qc2024
Multi-field TDiff theories for cosmology
Diego Tessainer, Antonio L. Maroto, Prado Martín-Moruno
We consider theories which break the invariance under diffeomorphisms (Diff) down to transverse diffeomorphisms (TDiff) in the matter sector, consisting of multiple scalar fields.…
gr-qc2024
Dark energy with a shift-symmetric scalar field: obstacles, loophole hunting and dead ends
Teodor Borislavov Vasilev, Mariam Bouhmadi-López, Prado Martín-Moruno
We discuss the possibility of a scalar field being the fundamental description of dark energy. We focus on shift-symmetric scalar-tensor theories since this symmetry potentially av…