López Maroto, AntonioBeltrán Jiménez, JoséKoivisto, Tomi S.Fonseca Mota, David2023-06-202023-06-202009-101475-751610.1088/1475-7516/2009/10/029https://hdl.handle.net/20.500.14352/44338© 2009 IOP Publishing Ltd and SISSA. This work has been supported by Ministerio de Ciencia e Innovación (Spain) project numbers FIS 2008-01323 and FPA 2008-00592, UCM-Santander PR34/07-15875. J.B. wishes to thank the Institute for Theoretical Physics of the University of Heidelberg for their hospitality.It has been recently proposed that the presence of a temporal electromagnetic field on cosmological scales could explain the phase of accelerated expansion that the universe is currently undergoing. The field contributes as a cosmological constant and therefore, the homogeneous cosmology produced by such a model is exactly the same as that of Lambda CDM. However, unlike a cosmological constant term, electromagnetic fields can acquire perturbations which in principle could affect CMB anisotropies and structures formation. In this work, we study the evolution of inhomogeneous scalar perturbations in this model. We show that provided the initial electromagnetic fluctuations generated during inflation are small, the model is perfectly compatible with both CMB and large scale structure observations at the same level of accuracy as Lambda CDM.engjournal articlehttp://dx.doi.org/10.1088/1475-7516/2009/10/029http://arxiv.org/abs/0907.3648http://iopscience.iop.orgopen access53Microwave-Anisotropy-ProbeEquation-of-State5-Year Wmap DataMagnetic FieldsSupernovaeInflationCosmologyUniverseVectorModelsFísica (Física)22 Física