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Author Capozziello, S.; Harko, T.; Koivisto, T.S.; Lobo, F.S.N.; Olmo, G.J.
Title Wormholes supported by hybrid metric-Palatini gravity Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 86 Issue 12 Pages (down) 127504 - 5pp
Keywords
Abstract Recently, a modified theory of gravity was presented, which consists of the superposition of the metric Einstein-Hilbert Lagrangian with an f(R) term constructed a la Palatini. The theory possesses extremely interesting features such as predicting the existence of a long-range scalar field, that explains the late-time cosmic acceleration and passes the local tests, even in the presence of a light scalar field. In this brief report, we consider the possibility that wormholes are supported by this hybrid metric-Palatini gravitational theory. We present here the general conditions for wormhole solutions according to the null energy conditions at the throat and find specific examples. In the first solution, we specify the redshift function, the scalar field and choose the potential that simplifies the modified Klein-Gordon equation. This solution is not asymptotically flat and needs to be matched to a vacuum solution. In the second example, by adequately specifying the metric functions and choosing the scalar field, we find an asymptotically flat spacetime.
Address [Capozziello, Salvatore] Univ Naples Federico II, Dipartimento Sci Fis, I-80126 Naples, Italy, Email: capozzie@na.infn.it;
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:000312446600010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1280
Permanent link to this record
 
 
Author Anderson, P.R.; Siahmazgi, S.G.; Clark, R.D.; Fabbri, A.
Title Method to compute the stress-energy tensor for a quantized scalar field when a black hole forms from the collapse of a null shell Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 102 Issue 12 Pages (down) 125035 - 26pp
Keywords
Abstract A method is given to compute the stress-energy tensor for a massless minimally coupled scalar field in a spacetime where a black hole forms from the collapse of a spherically symmetric null shell in four dimensions. Part of the method involves matching the modes for the in vacuum state to a complete set of modes in Schwarzschild spacetime. The other part involves subtracting from the unrenormalized expression for the stress-energy tensor when the field is in the in vacuum state, the corresponding expression when the field is in the Unruh state and adding to this the renormalized stress-energy tensor for the field in the Unruh state. The method is shown to work in the two-dimensional case where the results are known.
Address [Anderson, Paul R.; Siahmazgi, Shohreh Gholizadeh; Clark, Raymond D.] Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA, Email: anderson@wfu.edu;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language Spanish 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:000604246500005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4673
Permanent link to this record
 
 
Author Binosi, D.; Ibañez, D.; Papavassiliou, J.
Title QCD effective charge from the three-gluon vertex of the background-field method Type Journal Article
Year 2013 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 87 Issue 12 Pages (down) 125026 - 10pp
Keywords
Abstract In this article we study in detail the prospects of determining the infrared finite QCD effective charge from a special kinematic limit of the vertex function corresponding to three background gluons. This particular Green's function satisfies a QED-like Ward identity, relating it to the gluon propagator, with no reference to the ghost sector. Consequently, its longitudinal form factors may be expressed entirely in terms of the corresponding gluon wave function, whose inverse is proportional to the effective charge. After reviewing certain important theoretical properties, we consider a typical lattice quantity involving this vertex, and derive its exact dependence on the various form factors, for arbitrary momenta. We then focus on the particular momentum configuration that eliminates any dependence on the (unknown) transverse form factors, projecting out only the desired quantity. A preliminary numerical analysis indicates that the effective charge is relatively insensitive to the numerical uncertainties that may afflict future simulations of the aforementioned lattice quantity. The numerical difficulties associated with a parallel determination of the dynamical gluon mass are briefly discussed.
Address [Binosi, D.] European Ctr Theoret Studies Nucl Phys & Related, I-38123 Villazzano, Trento, Italy
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:000320609200011 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1490
Permanent link to this record
 
 
Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J.
Title Nonperturbative gluon and ghost propagators for d=3 Yang-Mills theory Type Journal Article
Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 81 Issue 12 Pages (down) 125025 - 13pp
Keywords
Abstract We study a manifestly gauge-invariant set of Schwinger-Dyson equations to determine the non-perturbative dynamics of the gluon and ghost propagators in d = 3 Yang-Mills theory. The use of the well-known Schwinger mechanism, in the Landau gauge leads to the dynamical generation of a mass for the gauge boson (gluon in d = 3), which, in turn, gives rise to an infrared finite gluon propagator and ghost dressing function. The propagators obtained from the numerical solution of these nonperturbative equations are in very good agreement with the results of SU(2) lattice simulations.
Address [Aguilar, A. C.] Fed Univ ABC, CCNH, BR-09210170 Santo Andre, Brazil
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 ISI:000279165900006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 422
Permanent link to this record
 
 
Author Ferreiro, A.; Navarro-Salas, J.
Title Pair creation in electric fields, anomalies, and renormalization of the electric current Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 97 Issue 12 Pages (down) 125012 - 13pp
Keywords
Abstract We investigate the Schwinger pair production phenomena in spatially homogeneous strong electric fields. We first consider scalar QED in four-dimensions and discuss the potential ambiguity in the adiabatic order assignment for the electromagnetic potential required to fix the renormalization subtractions. We argue that this ambiguity can be solved by invoking the conformal anomaly when both electric and gravitational backgrounds are present. We also extend the adiabatic regularization method for spinor QED in two-dimensions and find consistency with the chiral anomaly. We focus on the issue of the renormalization of the electric current < j(mu)> generated by the created pairs. We illustrate how to implement the renormalization of the electric current for the Sauter pulse.
Address [Ferreiro, Antonio; Navarro-Salas, Jose] Univ Valencia, Dept Fis Teor, Ctr Mixto, CSIC,Fac Fis, 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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000435335000014 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3623
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 (down) 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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000451998400004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3824
Permanent link to this record
 
 
Author Marañon-Gonzalez, F.J.; Navarro-Salas, J.
Title Adiabatic regularization for spin-1 fields Type Journal Article
Year 2023 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 108 Issue 12 Pages (down) 125001 - 11pp
Keywords
Abstract We analyze the adiabatic regularization scheme to renormalize Proca fields in a four-dimensional Friedmann-Lemaitre-Robertson-Walker spacetime. The adiabatic method is well established for scalar and spin-1/2 fields, but is not yet fully understood for spin-1 fields. We give the details of the construction and show that, in the massless limit, the renormalized stress-energy tensor of the Proca field is closely related to that of a minimally coupled scalar field. Our result is in full agreement with other approaches, based on the effective action, which also show a discontinuity in the massless limit. The scalar field can be naturally regarded as a Stueckelberg-type field. We also test the consistency of our results in de Sitter space.
Address [Maranon-Gonzalez, F. Javier; Navarro-Salas, Jose] Univ Valencia, Dept Fis Teor, CSIC, Burjassot 46100, Valencia, Spain, Email: jnavarro@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:001121689900014 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5871
Permanent link to this record
 
 
Author Carlson, E.D.; Anderson, P.R.; Fabbri, A.; Fagnocchi, S.; Hirsch, W.H.; Klyap, S.A.
Title Semiclassical gravity in the far field limit of stars, black holes, and wormholes Type Journal Article
Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 82 Issue 12 Pages (down) 124070 - 24pp
Keywords
Abstract Semiclassical gravity is investigated in a large class of asymptotically flat, static, spherically symmetric spacetimes including those containing static stars, black holes, and wormholes. Specifically the stress-energy tensors of massless free spin 0 and spin 1/2 fields are computed to leading order in the asymptotic regions of these spacetimes. This is done for spin 0 fields in Schwarzschild spacetime using a WKB approximation. It is done numerically for the spin 1/2 field in Schwarzschild, extreme Reissner-Nordstrom, and various wormhole spacetimes. And it is done by finding analytic solutions to the leading order mode equations in a large class of asymptotically flat static spherically symmetric spacetimes. Agreement is shown between these various computational methods. It is found that, for all of the spacetimes considered, the energy density and pressure in the asymptotic region are proportional to r(-5) to leading order. Furthermore, for the spin 1/2 field and the conformally coupled scalar field, the stress-energy tensor depends only on the leading order geometry in the far field limit. This is also true for the minimally coupled scalar field for spacetimes containing either a static star or a black hole, but not for spacetimes containing a wormhole.
Address [Carlson, Eric D.; Anderson, Paul R.; Hirsch, William H.; Klyap, Sarah A.] Wake Forest Univ, Dept Phys, Winston Salem, NC 27109 USA, Email: ecarlson@wfu.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 1550-7998 ISBN Medium
Area Expedition Conference
Notes ISI:000286749400008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 531
Permanent link to this record
 
 
Author Agullo, I.; Landete, A.; Navarro-Salas, J.
Title Electric-magnetic duality and renormalization in curved spacetimes Type Journal Article
Year 2014 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 90 Issue 12 Pages (down) 124067 - 7pp
Keywords
Abstract We point out that the duality symmetry of free electromagnetism does not hold in the quantum theory if an arbitrary classical gravitational background is present. The symmetry breaks in the process of renormalization, as also happens with conformal invariance. We show that a similar duality anomaly appears for a massless scalar field in 1 + 1 dimensions.
Address [Agullo, Ivan; Landete, Aitor] 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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000348361600012 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2089
Permanent link to this record
 
 
Author Olmo, G.J.; Rubiera-Garcia, D.
Title Palatini f(R) black holes in nonlinear electrodynamics Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 84 Issue 12 Pages (down) 124059 - 14pp
Keywords
Abstract The electrically charged Born-Infeld black holes in the Palatini formalism for f(R) theories are analyzed. Specifically we study those supported by a theory f(R) = R +/- R(2)/R(P), where R(P) is Planck's curvature. These black holes only differ from their General Relativity counterparts very close to the center but may give rise to different geometrical structures in terms of inner horizons. The nature and strength of the central singularities are also significantly affected. In particular, for the model f(R) = R – R(2)/R(P) the singularity is shifted to a finite radius, r(+), and the Kretschmann scalar diverges only as 1/(r-r(+))(2).
Address [Olmo, Gonzalo J.] Univ Valencia, Ctr Mixto Univ Valencia CSIC, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000298666600005 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 878
Permanent link to this record