2026-06-08T01:07:43Zhttps://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

00925njm 22002777a 4500 dc López Maroto, Antonio author Beltrán Jiménez, José author 2010 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. 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 Dark energy in vector-tensor theories of gravity