Zobrazeno 1 - 10
of 36
pro vyhledávání: '"Graef, L. L."'
Publikováno v:
Universe. 2024; 10(9):371
We revisit the proposal that an energy transfer from dark energy into dark matter can be described in field theory by a first order phase transition. We analyze the model proposed in Ref. Abdalla et al. (2013), using updated constraints on the decay
Externí odkaz:
http://arxiv.org/abs/2403.04970
Publikováno v:
Phys. Rev. D 106, 103535 (2022)
We revisit the predictions for the duration of the inflationary phase after the bounce in loop quantum cosmology. We present our analysis for different classes of inflationary potentials that include the monomial power-law chaotic type of potentials,
Externí odkaz:
http://arxiv.org/abs/2206.14881
Publikováno v:
Phys. Rev. D 102, 103521 (2020)
We study and estimate probabilistic predictions for the duration of the preinflationary and slow-roll phases after the bounce in loop quantum cosmology, determining how the presence of radiation in the prebounce phase affects these results. We presen
Externí odkaz:
http://arxiv.org/abs/2009.13587
Autor:
Graef, L. L., Ramos, Rudnei O.
Publikováno v:
Phys. Rev. D 98, 023531 (2018)
Warm inflation is analyzed in the context of Loop Quantum Cosmology (LQC). The bounce in LQC provides a mean through which a Liouville measure can be defined, which has been used previously to characterize the a priori probability for inflation in LQ
Externí odkaz:
http://arxiv.org/abs/1805.05985
Publikováno v:
Journal of Cosmology and Astroparticle Physics, JCAP, v. 2017, p. 013-013, 2017
The current most accepted paradigm for the early universe cosmology, the inflationary scenario, shows a good agreement with the recent Cosmic Microwave Background (CMB) and polarization data. However, when the inflation consistency relation is relaxe
Externí odkaz:
http://arxiv.org/abs/1705.01961
Publikováno v:
JCAP 04(2017)004
We discuss scalar-tensor realizations of the Anamorphic cosmological scenario recently proposed by Ijjas and Steinhardt. Through an analysis of the dynamics of cosmological perturbations we obtain constraints on the parameters of the model. We also s
Externí odkaz:
http://arxiv.org/abs/1701.02654
We consider Parker particle production in the Ekpyrotic scenario (in particular in the New Ekpyrotic model) and show that the density of particles produced by the end of the phase of Ekpyrotic contraction is sufficient to lead to a hot state of matte
Externí odkaz:
http://arxiv.org/abs/1605.04670
Autor:
Graef, L. L., Brandenberger, R.
Publikováno v:
Journal of Cosmology and Astroparticle Physics, JCAP, v. 2015, p. 032-032, 2015
We study the proposal by Mersini et al. that the observed dark energy might be explained by the back-reaction of the set of tail modes in a theory with a dispersion relation in which the mode frequency decays exponentially in the trans-Planckian regi
Externí odkaz:
http://arxiv.org/abs/1505.02374
A new cosmic scenario with gravitationally induced particle creation is proposed. In this model the Universe evolves from an early to a late time de Sitter era, with the recent accelerating phase driven only by the negative creation pressure associat
Externí odkaz:
http://arxiv.org/abs/1406.5538
Publikováno v:
Physics Letters. B , v. 728, p. 400-406, 2014
The correspondence between cosmological models powered by a decaying vacuum energy density and gravitationally induced particle production is investigated. Although being physically different in the physics behind them we show that both classes of co
Externí odkaz:
http://arxiv.org/abs/1303.2075