Primordial magnetogenesis in a bouncing universe

Frion, Emmanuel; Pinto-Neto, Nelson; Vitenti, Sandro D. P.; Bergliaffa, Santiago Esteban Pérez

doi:10.1103/physrevd.101.103503

Cited by 16 publications

(13 citation statements)

References 94 publications

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“…According to Frion and collaborators [38], 10 3 t Planck < t 0 < 10 40 t Planck , that is t min 0 = 10 −41 s < t 0 < t max 0 = 10 −4 s. We show in Figure 7 the range of allowed values for m 0 (in units of solar masses M ) according to the three conditions described above: the black line indicates the condition √ 3Gm 0 /c 3 = t 0 . The light yellow zone corresponds to values of m 0 and t 0 such that √ 3Gm 0 /c 3 > t 0 , while the light red region satisfies the condition √ 3Gm 0 /c 3 < t 0 .…”

Section: Ifmentioning

confidence: 93%

Dynamical black hole in a bouncing universe

Pérez,

Bergliaffa,

Romero

2021

Preprint

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We analyze the causal structure of McVittie spacetime for a classical bouncing cosmological model. In particular, we compute the trapping horizons of the metric and integrate the trajectories of radial null geodesics before, during, and after the bounce takes place. In the contracting phase up to the occurrence of the bounce, a dynamical black hole is present. When the universe reaches a certain minimum scale, the trapping horizons disappear and the black hole ceases to exist. After the bounce, the central weak singularity becomes naked. In the expanding phase, for large positive values of the cosmic time, the behaviour of null geodesics indicates that the solution contains a black hole. These results suggest that neither a contracting nor an expanding universe can accommodate a black hole at all times.

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Section: Ifmentioning

confidence: 93%

Dynamical black hole in a bouncing universe

Pérez,

Bergliaffa,

Romero

2021

Preprint

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“…We choose a scale factor that provides a bounce, has a simple analytical form, and describes a realistic cosmological model [22,23]:…”

Section: Scale Factor Bouncing Cosmological Modelmentioning

confidence: 99%

“…The lower limit on T b , given by T b > 10 3 t Planck , is set to ensure the validity of the Wheeler-de Witt equation, which was employed to derive the scale factor (1) [22].…”

Section: Scale Factor Bouncing Cosmological Modelmentioning

confidence: 99%

Survival of black holes through a cosmological bounce

Pérez,

Romero

2022

Preprint

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We analyze whether a black hole can exist and survive in a universe that goes through a cosmological bounce. To this end, we investigate a central inhomogeneity embedded in a bouncing cosmological background modeled by the comoving generalized McVittie metric. Contrary to other dynamical metrics available in the literature, this solution allows for the interaction of the central object with the cosmological fluid. We show that the horizons associated with this metric change with cosmic time because they are coupled to the cosmic evolution as the mass of the central object is always proportional to the scale factor: it decreases during contraction and increases during expansion phases. After a full analysis of the causal structure of this spacetime, we determine that a dynamical black hole persists during the contraction, bounce, and expansion of the universe. This result implies that there is a class of bouncing models that admits black holes at all cosmological epochs. If these models are correct approximation to the real universe, then black holes surviving a cosmic collapse could play some role in the subsequent expanding phase.

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“…Our current understanding on the origin of large scale magnetic fields are broadly classified into: (1) the astrophysical origin associated with dynamo mechanism [19][20][21] and (2) the primordial origin where the magnetic field is generated from the primordial quantum fluctuations during the inflationary epoch , or during the bouncing phase of the universe [56][57][58][59][60][61]. Among all the models proposed so far, the inflationary magnetogenesis earned significant attention due to the fact that the inflation concomitantly solves the well known flatness and horizon problems and predicts almost scale invariant curvature perturbation which is in agreement with the Planck data [62][63][64][65][66][67] to a great precision.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore in order to get viable inflationary magnetogenesis models, the backreaction and the strong couping problem should be resolved in the model (one may see [22,28,51,73,74]). Apart from the inflationary set-up, the bouncing magnetogenesis models, where the magnetic field generation occurs from a non-singular bounce scenario, has also been proposed in the literature [56][57][58][59][60][61]. In most of the bouncing magnetogenesis models, the electromagnetic field couples with the bouncer (who drives the bounce), which in turn spoils the conformal symmetry of the electromagnetic action.…”

Section: Introductionmentioning

confidence: 99%

Inflationary magnetogenesis with reheating phase from higher curvature coupling

Bamba

Elizalde

Odintsov

et al. 2021

J. Cosmol. Astropart. Phys.

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We investigate the generation of helical magnetic fields and address the baryon asymmetry of the universe from an inflationary magnetogenesis scenario, in which the conformal and parity symmetries of the electromagnetic field are broken through its coupling the Ricci scalar and the Gauss-Bonnet invariant via the dual field tensor, so that the generated magnetic field can have a helical nature. It is demonstrated that if a reheating phase with non-zero e-fold numbers following inflation is taken into account, the energy density of the magnetic fields as well as their helicity spectrum evolve differently compared to those for the instantaneous reheating case. As a result, it is shown that in presence of the reheating phase, both the field strength of the generated magnetic fields and the resultant baryon asymmetry of the universe can be compatible with the observations. Furthermore, we find a viable constraint on the reheating equation of state parameter ω eff from the data of the cosmic microwave background radiation as 0.284 ω eff 0.2975, which is consistent with a negligible Schwinger backreaction.

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Primordial magnetogenesis in a bouncing universe

Cited by 16 publications

References 94 publications

Dynamical black hole in a bouncing universe

Dynamical black hole in a bouncing universe

Survival of black holes through a cosmological bounce

Inflationary magnetogenesis with reheating phase from higher curvature coupling

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