RT Journal Article T1 Einstein-Cartan-Dirac gravity with U(1) symmetry breaking A1 Cabral, Francisco A1 Lobo, Francisco S. N. A1 Rubiera García, Diego AB Einstein-Cartan theory is an extension of the standard formulation of General Relativity where torsion (the antisymmetric part of the affine connection) is non-vanishing. Just as the space-time metric is sourced by the stress-energy tensor of the matter fields, torsion is sourced via the spin density tensor, whose physical effects become relevant at very high spin densities. In this work we introduce an extension of the Einstein-Cartan-Dirac theory with an electromagnetic (Maxwell) contribution minimally coupled to torsion. This contribution breaks the U(1) gauge symmetry, which is suggested by the possibility of a torsion-induced phase transition in the early Universe, yielding new physics in extreme (spin) density regimes. We obtain the generalized gravitational, electromagnetic and fermionic field equations for this theory, estimate the strength of the corrections, and discuss the corresponding phenomenology. In particular, we briefly address some astrophysical considerations regarding the relevance of the effects which might take place inside ultra-dense neutron stars with strong magnetic fields (magnetars). PB Springer SN 1434-6044 YR 2019 FD 2019-12 LK https://hdl.handle.net/20.500.14352/6033 UL https://hdl.handle.net/20.500.14352/6033 LA eng NO © The Author(s) 2019FC is funded by the Fundacao para a Ciencia e a Tecnologia (FCT, Portugal) predoctoralGrant no. PD/BD/128017/2016. DRG is funded by the Atraccion de Talento Investigador programme of the Comunidad deMadrid, no. 2018-T1/TIC-10431, and acknowledges support from the FCT research Grant PTDC/FIS-PAR/31938/2017, the projects FIS2014-57387-C3-1-P and FIS2017-84440-C2-1-P(MINECO/FEDER, EU), the project SEJI/2017/042 (Generalitat Valenciana), the Edital 006/2018 PRONEX (FAPESQ-PB/CNPQ, Brazil) and the EU COST Actions CA15117 and CA18108. FSNL acknowledges support from the Scientific Employment Stimulus contract with reference CEECIND/04057/2017. The authors also acknowledge funding from FCT projects nos. UID/FIS/04434/2019 and PTDC/FISOUT/29048/2017. Finally, the authors thank the anonymous referee for extremely helpful comments and suggestions. NO Unión Europea. H2020 NO Ministerio de Economía y Competitividad (MINECO)/FEDER NO Comunidad de Madrid NO Generalitat Valenciana NO Fundação para a Ciência e a Tecnologia (FCT) NO Scientific Employment Stimulus contract DS Docta Complutense RD 29 abr 2024