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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 (down) 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 [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
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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 (down) 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 [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 Ferreiro, A.; Navarro-Salas, J.; Pla, S.
Title R-summed form of adiabatic expansions in curved spacetime Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 101 Issue 10 Pages (down) 105011 - 12pp
Keywords
Abstract The Feynman propagator in curved spacetime admits an asymptotic (Schwinger-DeWitt) series expansion in derivatives of the metric. Remarkably, all terms in the series containing the Ricci scalar R can be summed exactly. We show that this (nonperturbative) property of the Schwinger-DeWitt series has a natural and equivalent counterpart in the adiabatic (Parker-Fulling) series expansion of the scalar modes in an homogeneous cosmological spacetime. The equivalence between both R-summed adiabatic expansions can be further extended when a background scalar field is also present.
Address [Ferreiro, Antonio] Univ Valencia, CSIC, Fac Fis, Ctr Mixto,Dept Fis Teor, Valencia 46100, 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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000532656100007 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4395
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 (down) 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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000468223500013 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4011
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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 (down) 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 [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