Records |
Author |
Navarro-Salas, J.; Pla, S. |
Title |
Particle Creation and the Schwinger Model |
Type |
Journal Article |
Year |
2022 |
Publication |
Symmetry-Basel |
Abbreviated Journal |
Symmetry-Basel |
Volume |
14 |
Issue |
11 |
Pages |
2435 - 9pp |
Keywords |
Schwinger model; semiclassical theory; particle creation |
Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
We study the particle creation process in the Schwinger model coupled with an external classical source. One can approach the problem by taking advantage of the fact that the full quantized model is solvable and equivalent to a (massive) gauge field with a non-local effective action. Alternatively, one can also face the problem by following the standard semiclassical route. This means quantizing the massless Dirac field and considering the electromagnetic field as a classical background. We evaluate the energy created by a generic, homogeneous, and time-dependent source. The results match exactly in both approaches. This proves in a very direct and economical way the validity of the semiclassical approach for the (massless) Schwinger model, in agreement with a previous analysis based on the linear response equation. Our discussion suggests that a similar analysis for the massive Schwinger model could be used as a non-trivial laboratory to confront a fully quantized solvable model with its semiclassical approximation, therefore mimicking the long-standing confrontation of quantum gravity with quantum field theory in curved spacetime. |
Address |
[Navarro-Salas, Jose] Univ Valencia, Ctr Mixto Univ Valencia CSIC, Fac Fis, Dept Fis Teor & IFIC, Burjassot 46100, Valencia, Spain, Email: jnavarro@ific.uv.es |
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Thesis |
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Publisher |
Mdpi |
Place of Publication |
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English |
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Expedition |
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Conference |
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Notes |
WOS:000895122100001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5432 |
Permanent link to this record |
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Author |
Agullo, I.; Navarro-Salas, J.; Olmo, G.J.; Parker, L. |
Title |
Revising the observable consequences of slow-roll inflation |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
81 |
Issue |
4 |
Pages |
043514 - 14pp |
Keywords |
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Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
We study the generation of primordial perturbations in a (single-field) slow-roll inflationary Universe. In momentum space, these (Gaussian) perturbations are characterized by a zero mean and a nonzero variance Delta(2) (k, t). However, in position space the variance diverges in the ultraviolet. The requirement of a finite variance in position space forces one to regularize Delta(2) (k, t). This can (and should) be achieved by proper renormalization in an expanding Universe in a unique way. This affects the predicted scalar and tensorial power spectra (evaluated when the modes acquire classical properties) for wavelengths that today are at observable scales. As a consequence, the imprint of slow-roll inflation on the cosmic microwave background anisotropies is significantly altered. We find a nontrivial change in the consistency condition that relates the tensor-to-scalar ratio r to the spectral indices. For instance, an exact scale-invariant tensorial power spectrum, n(t) = 0, is now compatible with a nonzero ratio r approximate to 0.12 +/- 0.06, which is forbidden by the standard prediction (r = -8n(t)). The influence of relic gravitational waves on the cosmic microwave background may soon come within the range of planned measurements, offering a nontrivial test of the new predictions. |
Address |
[Agullo, Ivan; Olmo, Gonzalo J.; Parker, Leonard] Univ Wisconsin, Dept Phys, Milwaukee, WI 53201 USA, Email: ivan.agullo@uv.es |
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Publisher |
Amer Physical Soc |
Place of Publication |
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English |
Summary Language |
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Series Editor |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000275898500028 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
479 |
Permanent link to this record |
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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 |
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Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
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 |
[del Rio, Adrian; Navarro-Salas, Jose] Univ Valencia, Dept Fis Teor, E-46100 Burjassot, Valencia, Spain, Email: adrian.rio@uv.es; |
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Publisher |
Amer Physical Soc |
Place of Publication |
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English |
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ISSN |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000343773100003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
1985 |
Permanent link to this record |
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Author |
del Rio, A.; Navarro-Salas, J. |
Title |
Equivalence of adiabatic and DeWitt-Schwinger renormalization schemes |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
91 |
Issue |
6 |
Pages |
064031 - 14pp |
Keywords |
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Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
We prove that adiabatic regularization and DeWitt-Schwinger point-splitting provide the same result when renormalizing expectation values of the stress-energy tensor for spin-1/2 fields. This generalizes the equivalence found for scalar fields, which is here recovered in a different way. We also argue that the coincidence limit of the DeWitt-Schwinger proper time expansion of the two-point function agrees exactly with the analogous expansion defined by the adiabatic regularization method at any order (for both scalar and spin-1/2 fields). We also illustrate the power of the adiabatic method to compute higher order DeWitt coefficients in Friedmann-Lemaitre-Robertson-Walker Universes. |
Address |
[del Rio, Adrian; Navarro-Salas, Jose] Univ Valencia, Dept Fis Teor, IFIC, Ctr Mixto,CSIC,Fac Fis, E-46100 Valencia, Spain, Email: adrian.rio@uv.es; |
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Thesis |
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Publisher |
Amer Physical Soc |
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Language |
English |
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ISSN |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000350966000005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
2150 |
Permanent link to this record |
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Author |
Ferreiro, A.; Navarro-Salas, J. |
Title |
Running gravitational couplings, decoupling, and curved spacetime renormalization |
Type |
Journal Article |
Year |
2020 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
102 |
Issue |
4 |
Pages |
045021 - 6pp |
Keywords |
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Abstract ![sorted by Abstract field, descending order (down)](img/sort_desc.gif) |
We propose to slightly generalize the DeWitt-Schwinger adiabatic renormalization subtractions in curved space to include an arbitrary renornialization mass scale mu. The new predicted running for the gravitational couplings are fully consistent with decoupling of heavy massive fields. This is a somewhat improvement with respect to the more standard treatment of minimal (DeWitt-Schwinger) subtractions via dimensional regularization. We also show how the vacuum metamorphosis model emerges from the running couplings. |
Address |
[Ferreiro, Antonio; Navarro-Salas, Jose] Univ Valencia, Fac Fis, CSIC, Ctr Mixto Univ Valencia,Dept Fis Teor, Valencia 46100, Spain, Email: antonio.ferreiro@ific.uv.es; |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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ISSN |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000563711800009 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
4517 |
Permanent link to this record |