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Author Barbero, J.F.; Ferreiro, A.; Navarro-Salas, J.; Villaseñor, E.J.S.
Title Adiabatic expansions for Dirac fields, renormalization, and anomalies Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 2 Pages 025016 - 11pp
Keywords
Abstract We introduce an iterative method to univocally determine the adiabatic expansion of the modes of Dirac fields in spatially homogeneous external backgrounds. We overcome the ambiguities found in previous studies and use this new procedure to improve the adiabatic regularization/renormalization scheme. We provide details on the application of the method for Dirac fields living in a four-dimensional Friedmann-Lemaitre-Robertson-Walker spacetime with a Yukawa coupling to an external scalar field. We check the consistency of our proposal by working out the conformal anomaly. We also analyze a two-dimensional Dirac field in Minkowski space coupled to a homogeneous electric field and reproduce the known results on the axial anomaly. The adiabatic expansion of the modes given here can be used to properly characterize the allowed physical states of the Dirac fields in the above external backgrounds.
Address [Barbero G, J. Fernando] CSIC, Inst Estruct Mat, E-28006 Madrid, Spain, Email: fbarbero@iem.cfmac.csic.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000439414000006 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3673
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Author Ferreiro, A.; Navarro-Salas, J.; Pla, S.
Title Role of gravity in the pair creation induced by electric fields Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 4 Pages 045015 - 6pp
Keywords
Abstract We analyze the pair production induced by homogenous, time-dependent electric fields in an expanding space-time background. We point out that, in obtaining the semiclassical Maxwell equations, two distinct notions of adiabatic renormalization are possible. In Minkowski space, the two recipes turn out to be equivalent. However, in the presence of gravity, only the recipe requiring an adiabatic hierarchy between the gravitational and the gauge field is consistent with the conservation of the energy-momentum tensor.
Address [Ferreiro, Antonio; Navarro-Salas, Jose; Pla, Silvia] Univ Valencia, Fac Fis, Dept Fis Teor, Ctr Mixto Univ Valencia CSIC, E-46100 Valencia, Spain, Email: antonio.ferreiro@ific.uv.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000442476700003 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3703
Permanent link to this record
 

 
Author Agullo, I.; del Rio, A.; Navarro-Salas, J.
Title Classical and quantum aspects of electric-magnetic duality rotations in curved spacetimes Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 12 Pages 125001 - 22pp
Keywords
Abstract It is well known that the source-free Maxwell equations are invariant under electric-magnetic duality rotations, F -> F cos theta +*F sin theta. These transformations are indeed a symmetry of the theory in the Noether sense. The associated constant of motion is the difference in the intensity between self-dual and anti-self-dual components of the electromagnetic field or, equivalently, the difference between the right and left circularly polarized components. This conservation law holds even if the electromagnetic field interacts with an arbitrary classical gravitational background. After reexamining these results, we discuss whether this symmetry is maintained when the electromagnetic field is quantized. The answer is in the affirmative in the absence of gravity but not necessarily otherwise. As a consequence, the net polarization of the quantum electromagnetic field fails to be conserved in curved spacetimes. This is a quantum effect, and it can be understood as the generalization of the fermion chiral anomaly to fields of spin one.
Address [Agullo, Ivan] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA, Email: agullo@lsu.edu;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000451998400004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3824
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Author Beltran-Palau, P.; Navarro-Salas, J.; Pla, S.
Title Translational anomaly of chiral fermions in two dimensions Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 10 Pages 105008 - 5pp
Keywords
Abstract It is well known that a quantized two-dimensional Weyl fermion coupled to gravity spoils general covariance and breaks the covariant conservation of the energy-momentum tensor. In this brief article, we point out that the quantum conservation of the momentum can also fail in flat spacetime, provided the Weyl fermion is coupled to a time-varying homogeneous electric field. This signals a quantum anomaly of the space-translation symmetry, which has not been highlighted in the literature so far.
Address [Beltran-Palau, Pau; Navarro-Salas, Jose; Pla, Silvia] Univ Valencia, Dept Fis Teor, Ctr Mixto, CSIC,Fac Fis, E-46100 Valencia, Spain, Email: pau.beltran@uv.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000468223500013 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4011
Permanent link to this record
 

 
Author Beltran-Palau, P.; Ferreiro, A.; Navarro-Salas, J.; Pla, S.
Title Breaking of adiabatic invariance in the creation of particles by electromagnetic backgrounds Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 100 Issue 8 Pages 085014 - 12pp
Keywords
Abstract Particles are spontaneously created from the vacuum by time-varying gravitational or electromagnetic backgrounds. It has been proven that the particle number operator in an expanding universe is an adiabatic invariant. In this paper we show that, in some special cases, the expected adiabatic invariance of the particle number fails in presence of electromagnetic backgrounds. In order to do this, we consider as a prototype a Sauter-type electric pulse. Furthermore, we also show a close relation between the breaking of the adiabatic invariance and the emergence of the axial anomaly.
Address [Beltran-Palau, Pau; Ferreiro, Antonio; Navarro-Salas, Jose; Pla, Silvia] Univ Valencia, CSIC, Ctr Mixto, Fac Fis,Dept Fis Teor, E-46100 Valencia, Spain, Email: pau.beltran@uv.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000491467800009 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4184
Permanent link to this record