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Author Agullo, I.; Navarro-Salas, J.; Olmo, G.J.; Parker, L.
Title Remarks on the renormalization of primordial cosmological perturbations Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 84 Issue 10 Pages 107304 - 5pp
Keywords
Abstract We briefly review the need to perform renormalization of inflationary perturbations to properly work out the physical power spectra. We also summarize the basis of (momentum-space) renormalization in curved spacetime and address several misconceptions found in recent literature on this subject.
Address (up) [Agullo, I] Penn State Univ, Dept Phys, Inst Gravitat & Cosmos, University Pk, PA 16802 USA
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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000297126700004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 811
Permanent link to this record
 
 
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 (up) [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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000439414000006 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3673
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 (up) [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 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
 
 
Author Beltran-Palau, P.; del Rio, A.; Nadal-Gisbert, S.; Navarro-Salas, J.
Title Note on the pragmatic mode-sum regularization method: Translational-splitting in a cosmological background Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 103 Issue 10 Pages 105002 - 9pp
Keywords
Abstract The point-splitting renormalization method offers a prescription to calculate finite expectation values of quadratic operators constructed from quantum fields in a general curved spacetime. It has been recently shown by Levi and Ori that when the background metric possesses an isometry, like stationary or spherically symmetric black holes, the method can be upgraded into a pragmatic procedure of renormalization that produces efficient numerical calculations. In this paper we show that when the background enjoys three-dimensional spatial symmetries, like homogeneous expanding universes, the above pragmatic regularization technique reduces to the well-established adiabatic regularization method.
Address (up) [Beltran-Palau, Pau; Nadal-Gisbert, Sergi; Navarro-Salas, Jose] Univ Valencia, Dept Fis Teor, Ctr Mixto, CSIC,Fac Fis, Valencia 46100, 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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000655874400009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4845
Permanent link to this record
 
 
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 (up) [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 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.; Navarro-Salas, J.; Pla, S.
Title Adiabatic regularization for Dirac fields in time-varying electric backgrounds Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 101 Issue 10 Pages 105014 - 15pp
Keywords
Abstract The adiabatic regularization method was originally proposed by Parker and Fulling to renormalize the energy-momentum tensor of scalar fields in expanding universes. It can be extended to renormalize the electric current induced by quantized scalar fields in a time-varying electric background. This can be done in a way consistent with gravity if the vector potential is considered as a variable of adiabatic order one. Assuming this, we further extend the method to deal with Dirac fields in four space-time dimensions. This requires a self-consistent ansatz for the adiabatic expansion, in presence of a prescribed time-dependent electric field, which is different from the conventional expansion used for scalar fields. Our proposal is consistent, in the massless limit, with the conformal anomaly. We also provide evidence that our proposed adiabatic expansion for the fermionic modes parallels the Schwinger-DeWitt adiabatic expansion of the two-point function. We give the renormalized expression of the electric current and analyze, using numerical and analytical tools, the pair production induced by a Sauter-type electric pulse. We also analyze the scaling properties of the current for a large field strength.
Address (up) [Beltran-Palau, Pau; Navarro-Salas, Jose; Pla, Silvia] Univ Valencia, Fac Fis, Ctr Mixto Univ Valencia CSIC, Dept Fis Teor, Valencia 46100, 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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000534174400011 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4399
Permanent link to this record
 
 
Author Beltran-Palau, P.; del Rio, A.; Navarro-Salas, J.
Title Quantum corrections to the Schwarzschild metric from vacuum polarization Type Journal Article
Year 2023 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 107 Issue 8 Pages 085023 - 15pp
Keywords
Abstract We explore static and spherically symmetric solutions of the 4-dimensional semiclassical Einstein's equations using the quantum vacuum polarization of a conformal field as a source. These solutions may be of interest for the study of exotic compact objects (ECOs). The full backreaction problem is addressed by solving the semiclassical Tolman-Oppenheimer-Volkoff (TOV) equations making use of effective equations of state inspired by the trace anomaly and an extra simplifying and reasonable assumption. We combine analytical and numerical techniques to solve the resulting differential equations, both perturbatively and nonperturbatively in h. In all cases the solution is similar to the Schwarzschild metric up p ffiffito the vicinity of the classical horizon r = 2M. However, at r = 2M + epsilon, with epsilon similar to O(root h), we find a coordinate singularity. In the case of matching with a static star, this leads to an upper bound in the compactness, and sets a constraint on the family of stable ECOs. We also study the corrections that the quantum-vacuum polarization induces on the propagation of waves, and discuss the implications. For the pure vacuum case, we can further extend the solution by using appropriate coordinates until we reach another singular point, where this time a null curvature singularity arises and prevents extending beyond. This picture qualitatively agrees with the results obtained in the effective two-dimensional approach, and reinforces the latter as a reasonable method.
Address (up) [Beltran-Palau, Pau; Navarro-Salas, Jose] Univ Valencia, Dept Fis Teor, Burjassot 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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000988649200017 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5543
Permanent link to this record
 
 
Author Bernabeu, J.; Navarro-Salas, J.
Title A Non-Local Action for Electrodynamics: Duality Symmetry and the Aharonov-Bohm Effect, Revisited Type Journal Article
Year 2019 Publication Symmetry-Basel Abbreviated Journal Symmetry-Basel
Volume 11 Issue 10 Pages 1191 - 13pp
Keywords non-local action; electrodynamics; electromagnetic duality symmetry; Aharonov-Bohm effect
Abstract A non-local action functional for electrodynamics depending on the electric and magnetic fields, instead of potentials, has been proposed in the literature. In this work we elaborate and improve this proposal. We also use this formalism to confront the electric-magnetic duality symmetry of the electromagnetic field and the Aharonov-Bohm effect, two subtle aspects of electrodynamics that we examine in a novel way. We show how the former can be derived from the simple harmonic oscillator character of vacuum electrodynamics, while also demonstrating how the magnetic version of the latter naturally arises in an explicitly non-local manner.
Address (up) [Bernabeu, Joan] Ludwig Maximilians Univ Munchen, Phys Dept, Theresienstr 37, D-80333 Munich, Germany, Email: Joan.Bernabeu@physik.uni-muenchen.de;
Corporate Author Thesis
Publisher Mdpi Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes WOS:000495457600005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4192
Permanent link to this record
 
 
Author del Rio, A.; Ferreiro, A.; Navarro-Salas, J.; Torrenti, F.
Title Adiabatic regularization with a Yukawa interaction Type Journal Article
Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 95 Issue 10 Pages 105003 - 19pp
Keywords
Abstract We extend the adiabatic regularization method for an expanding universe to include the Yukawa interaction between quantized Dirac fermions and a homogeneous background scalar field. We give explicit expressions for the renormalized expectation values of the stress-energy tensor < T-mu nu > and the bilinear <(psi) over bar psi > in a spatially flat Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime. These are basic ingredients in the semiclassical field equations of fermionic matter in curved spacetime interacting with a background scalar field. The ultraviolet subtracting terms of the adiabatic regularization can be naturally interpreted as coming from appropriate counterterms of the background fields. We fix the required covariant counterterms. To test our approach we determine the contribution of the Yukawa interaction to the conformal anomaly in the massless limit and show its consistency with the heat-kernel method using the effective action.
Address (up) [del Rio, Adrian; Ferreiro, Antonio; Navarro-Salas, Jose] Univ Valencia, Fac Fis, Ctr Mixto Univ Valencia CSIC, Dept Fis Teor, E-46100 Valencia, Spain, Email: adrian.rio@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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000401447900006 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3127
Permanent link to this record
 
 
Author del Rio, A.; Navarro-Salas, J.; Torrenti, F.
Title Renormalized stress-energy tensor for spin-1/2 fields in expanding universes Type Journal Article
Year 2014 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 90 Issue 8 Pages 084017 - 15pp
Keywords
Abstract We provide an explicit expression for the renormalized expectation value of the stress-energy tensor of a spin-1/2 field in a spatially flat Friedmann-Lemaitre-Robertson-Walker universe. Its computation is based on the extension of the adiabatic regularization method to fermion fields introduced recently in the literature. The tensor is given in terms of UV-finite integrals in momentum space, which involve the mode functions that define the quantum state. As illustrative examples of the method efficiency, we see how to compute the renormalized energy density and pressure in two interesting cosmological scenarios: a de Sitter spacetime and a radiation-dominated universe. In the second case, we explicitly show that the late-time renormalized stress-energy tensor behaves as that of classical cold matter. We also check that, if we obtain the adiabatic expansion of the scalar field mode functions with a similar procedure to the one used for fermions, we recover the well-known WKB-type expansion.
Address (up) [del Rio, Adrian; Navarro-Salas, Jose] Univ Valencia, Dept Fis Teor, E-46100 Burjassot, Valencia, Spain, Email: adrian.rio@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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000343773100003 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1985
Permanent link to this record