2026-06-08T12:21:39Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/442972023-08-25T19:19:24Zcom_20.500.14352_14col_20.500.14352_15

López Maroto, Antonio Beltrán Jiménez, José 2023-06-20T03:42:41Z 2023-06-20T03:42:41Z 2010 1742-6588 10.1088/1742-6596/229/1/012019 https://hdl.handle.net/20.500.14352/44297 http://dx.doi.org/10.1088/1742-6596/229/1/012019 http://iopscience.iop.org We consider a general class of vector-tensor theories of gravity and show that solutions with accelerated expansion and a future type III singularity are a common feature in these models. We also show that there are only six vector tensor theories with the same small scales behaviour as General Relativity and, in addition, only two of them can be made completely free from instabilities. Finally, two particular models as candidates for dark energy are proposed: on one hand, a cosmic vector that allows to alleviate the usual naturalness and coincidence problems and, on the other hand, the electromagnetic field is shown to give rise to an effective cosmological constant on large scales whose value can be explained in terms of inflation at the electroweak scale. eng https://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Dark energy in vector-tensor theories of gravity journal article