Reheating in non-minimal derivative coupling model

Sadjadi, H. Mohseni; Goodarzi, Parviz

doi:10.1088/1475-7516/2013/02/038

Cited by 64 publications

(82 citation statements)

References 34 publications

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“…In addition to this, there is a unique nonminimal derivative coupling of the Standard Model Higgs boson to gravity which propagates no more degrees of freedom than General Relativity sourced by a scalar field, and reproduces a successful inflating background within the Standard Model Higgs parameters and, finally, does not suffer from dangerous quantum corrections [51]. The slow-roll conditions have been found [52], and the reheating temperature was obtained [53,54] (see also recent analyses in [55] and [56]). Furthermore, the cosmological perturbations originated at the inflationary stage were studied and the consistency of the results with observational constraints coming from Planck 2013 data were investigated [57].…”

Section: Introductionmentioning

confidence: 81%

Cosmological models in modified gravity theories with extended nonminimal derivative couplings

2017

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We construct gravitational modifications that go beyond Horndeski, namely theories with extended nonminimal derivative couplings, in which the coefficient functions depend not only on the scalar field but also on its kinetic energy. Such theories prove to be ghost-free in a cosmological background. We investigate the early-time cosmology and show that a de Sitter inflationary phase can be realized as a pure result of the novel gravitational couplings. Additionally, we study the latetime evolution, where we obtain an effective dark energy sector which arises from the scalar field and its extended couplings to gravity. We extract various cosmological observables and analyse their behavior at small redshifts for three choices of potentials, namely, for the exponential, the powerlaw, and the Higgs potential. We show that the Universe passes from deceleration to acceleration in the recent cosmological past, while the effective dark-energy equation-of-state parameter tends to the cosmological-constant value at present. Finally, the effective dark energy can be phantom-like, although the scalar field is canonical, which is an advantage of the model.PACS numbers: 04.50. Kd, 95.36.+x

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Section: Introductionmentioning

confidence: 81%

Cosmological models in modified gravity theories with extended nonminimal derivative couplings

2017

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“…The simplest models are those with non-minimally coupled [60][61][62][63] and non-minimal-derivatively coupled [64][65][66][67][68] scalar fields, but one could further use arbitrary functions of the kinetic and potential parts such as in K-essence [69], resulting in the general Horndeski [70] and generalized Galileon theories [71][72][73]. However, since there is no theoretical reason against couplings between the gravitational sector and the standard matter one, one can consider modified theories where the matter Lagrangian is coupled to functions of the Ricci scalar [74][75][76][77], and extend the theory to arbitrary functions (R, L m ) [78][79][80][81][82].…”

Section: Contents 1 Introductionmentioning

confidence: 99%

f(T,𝒯) gravity and cosmology

Harkó

Lobo

Otalora

et al. 2014

J. Cosmol. Astropart. Phys.

265

213

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Abstract. We present an extension of f (T ) gravity, allowing for a general coupling of the torsion scalar T with the trace of the matter energy-momentum tensor T . The resulting f (T, T ) theory is a new modified gravity, since it is different from all the existing torsion or curvature based constructions. Applied to a cosmological framework, it leads to interesting phenomenology. In particular, one can obtain a unified description of the initial inflationary phase, the subsequent non-accelerating, matter-dominated expansion, and then the transition to a late-time accelerating phase. Additionally, the effective dark energy sector can be quintessence or phantom-like, or exhibit the phantom-divide crossing during the evolution. Moreover, in the far future the universe results either to a de Sitter exponential expansion, or to eternal power-law accelerated expansions. Finally, a detailed study of the scalar perturbations at the linear level reveals that f (T, T ) cosmology can be free of ghosts and instabilities for a wide class of ansatzes and model parameters.

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“…[77,90]). Inflationary scenario of the model with quadratic potential and modifications of standard reheating by the NMDC term is found by Sadjadi and Goodarzi in 2013 [91]. Tsujikawa in 2012 showed that, due to gravitational friction produced by the NMDC, even with steep potentials, a class of inflationary potentials is compatible with observation [92].…”

Section: Model With Negative-sign Nmdcmentioning

confidence: 83%

Non-minimal derivative coupling gravity in cosmology

Gumjudpai

Rangdee

2015

Gen Relativ Gravit

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We give a brief review of the non-minimal derivative coupling (NMDC) scalar field theory in which there is non-minimal coupling between the scalar field derivative term and the Einstein tensor. We assume that the expansion is of power-law type or super-acceleration type for small redshift. The Lagrangian includes the NMDC term, a free kinetic term, a cosmological constant term and a barotropic matter term. For a value of the coupling constant that is compatible with inflation, we use the combined WMAP9 (WMAP9+eCMB+BAO+ H0) dataset, the PLANCK+WP dataset, and the PLANCK T T, T E, EE+lowP+Lensing+ext datasets to find the value of the cosmological constant in the model. Modeling the expansion with power-law gives a negative cosmological constants while the phantom power-law (super-acceleration) expansion gives positive cosmological constant with large error bar. The value obtained is of the same order as in the ΛCDM model, since at late times the NMDC effect is tiny due to small curvature.

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Reheating in non-minimal derivative coupling model

Cited by 64 publications

References 34 publications

Cosmological models in modified gravity theories with extended nonminimal derivative couplings

Cosmological models in modified gravity theories with extended nonminimal derivative couplings

f(T,𝒯) gravity and cosmology

Non-minimal derivative coupling gravity in cosmology

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