Deflationary cosmology with decaying vacuum energy density

Lima, J. A. S.; Maia, Joana

doi:10.1103/physrevd.49.5597

Cited by 160 publications

(175 citation statements)

References 34 publications

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“…The dynamical Λ(H)-term was phenomenologically modeled as Λ(H) = Λ b + H 3 /H I . This kind of model undergone a smooth transition from an early inflation to the standard radiation phase which can analytically be described [3,4,25,26]. Interestingly, the model explain the present day entropy content of the Universe stored in the relic radiation [27,28] without necessity of a highly non-adiabaticreheating stage.…”

Section: Final Commentsmentioning

confidence: 99%

“…As remarked before, it will be assumed here that the Λ(H)-term is given by a particular case of the general class studied by Perico et al [25,26] (for closely related works see also [3,4])…”

Section: The Model: Basic Equationsmentioning

confidence: 99%

“…Since long ago, many different phenomenological decay laws for Λ(H) were proposed in the literature (see [1,2,3,4,5] for the oldest literature and [6,7,8,9] for more recent articles). The predictions of the latest models have also been confronted with the available observational data and the results compared with the predictions of the standard ΛCDM cosmology [10,11].…”

Section: Introductionmentioning

confidence: 99%

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Primordial gravitational waves in running vacuum cosmologies

Tamayo

Lima

Alves

et al. 2017

Astroparticle Physics

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We investigate the cosmological production of gravitational waves in a nonsingular flat cosmology powered by a "running vacuum" energy density described by ρ Λ ≡ ρ Λ (H), a phenomenological expression potentially linked with the renormalization group approach in quantum field theory in curved spacetimes. The model can be interpreted as a particular case of the class recently discussed by Perico et al. (Phys. Rev. D 88, 063531, 2013) which is termed complete in the sense that the cosmic evolution occurs between two extreme de Sitter stages (early and late time de Sitter phases). The gravitational wave equation is derived and its time-dependent part numerically integrated since the primordial de Sitter stage. The generated spectrum of gravitons is also compared with the standard calculations where an abrupt transition, from the early de Sitter to the radiation phase, is usually assumed. It is found that the stochastic background of gravitons is very similar to the one predicted by the cosmic concordance model plus inflation except at higher frequencies (ν 100 kHz). This remarkable signature of a "running vacuum" cosmology combined with the proposed high frequency gravitational wave detectors and measurements of the CMB polarization (Bmodes) may provide a new window to confront more conventional models of inflation.

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Section: Final Commentsmentioning

confidence: 99%

Section: The Model: Basic Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Primordial gravitational waves in running vacuum cosmologies

Tamayo

Lima

Alves

et al. 2017

Astroparticle Physics

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“…Models of inflation based on higher order terms inspired by the RG framework have existed for a long time in the literature (see [14,15]), as well as the unified inflation-dark energy framework of [13]. For a more phenomenological treatment unrelated to the RG, see [83][84][85][86].…”

Section: "Decay" Of Effective Vacuum Energy: Running Vacuum Modelmentioning

confidence: 99%

Starobinsky-Like Inflation and Running Vacuum in the Context of Supergravity

2016

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Abstract:We describe the primeval inflationary phase of the early Universe within a quantum field theoretical (QFT) framework that can be viewed as the effective action of vacuum decay in the early times. Interestingly enough, the model accounts for the "graceful exit" of the inflationary phase into the standard radiation regime. The underlying QFT framework considered here is supergravity (SUGRA), more specifically an existing formulation in which the Starobinsky-type inflation (de Sitter background) emerges from the quantum corrections to the effective action after integrating out the gravitino fields in their (dynamically induced) massive phase. We also demonstrate that the structure of the effective action in this model is consistent with the generic idea of re-normalization group (RG) running of the cosmological parameters; specifically, it follows from the corresponding RG equation for the vacuum energy density as a function of the Hubble rate, ρ Λ (H). Overall, our combined approach amounts to a concrete-model realization of inflation triggered by vacuum decay in a fundamental physics context, which, as it turns out, can also be extended for the remaining epochs of the cosmological evolution until the current dark energy era.

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“…This scenario may alternatively be interpreted in the context of a decaying vacuum (cf. [9,10]). The energy density may be split into ρ = ρ (v) + ρ (r) , where…”

Section: Phenomenological Vacuum Decaymentioning

confidence: 99%

Conformal Symmetry and Deflationary Gas Universe

Zimdahl

Balakin

Exact Solutions and Scalar Fields in Gravity

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We describe the "deflationary" evolution from an initial de Sitter phase to a subsequent Friedmann-Lemaître-Robertson-Walker (FLRW) period as a specific non-equilibrium configuration of a self-interacting gas. The transition dynamics corresponds to a conformal, timelike symmetry of an "optical" metric, characterized by a refraction index of the cosmic medium which continously decreases from a very large initial value to unity in the FLRW phase.

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Deflationary cosmology with decaying vacuum energy density

Cited by 160 publications

References 34 publications

Primordial gravitational waves in running vacuum cosmologies

Primordial gravitational waves in running vacuum cosmologies

Starobinsky-Like Inflation and Running Vacuum in the Context of Supergravity

Conformal Symmetry and Deflationary Gas Universe

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