Do the cosmological observational data prefer phantom dark energy?

Novosyadlyj, B.; Sergijenko, O.; Durrer, Ruth; Pelykh, V. O.

doi:10.1103/physrevd.86.083008

Cited by 57 publications

(77 citation statements)

References 62 publications

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“…Despite the problems at the level of cosmological perturbations arising from Eq. (64), the scalar field model (62) is actually better in agreement with the latest astronomical observations which favour a value w φ < −1 at present, though the minus one value still lies inside the 2-sigma confidence limit [15,16]. The scalar field (62) can thus characterize a quintom scenario where the crossing of the phantom barrier happens at late times with the universe being nowadays dark energy dominated (w eff > −1) but evolving through a final phantom era (w eff < −1).…”

Section: Square Root Kinetic Correctionssupporting

confidence: 74%

“…In this work we will only consider exponential potential of the kind (16). With this assumption the acceleration equation (7) and the scalar field equation (8) lead to the two dimensional autonomous system…”

Section: The Canonical Scalar Fieldmentioning

confidence: 99%

“…In other words, for a scalar field EoS p φ = w φ ρ φ , the phantom regime is identified by the condition w φ < −1, which seems to be slightly favoured by astronomical observations even after Planck [15,16]. The first and simplest model capable of achiving such condition consists in flipping the sign of the kinetic term of a canonical scalar field [17].…”

Section: Introductionmentioning

confidence: 99%

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Dynamics of cosmological scalar fields

Tamanini

2014

Phys. Rev. D

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The background dynamical evolution of a universe filled with matter and a cosmological scalar field is analyzed employing dynamical system techniques. After the phenomenology of a canonical scalar field with exponential potential is revised, square and square root kinetic corrections to the scalar field canonical Lagrangian are considered and the resulting dynamics at cosmological distances is obtained and studied. These noncanonical cosmological models imply new interesting phenomenology including early time matter dominated solutions, cosmological scaling solutions and late time phantom dominated solutions with dynamical crossing of the phantom barrier. Stability and viability issues for these scalar fields are presented and discussed.

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Section: Square Root Kinetic Correctionssupporting

confidence: 74%

Section: The Canonical Scalar Fieldmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Dynamics of cosmological scalar fields

Tamanini

2014

Phys. Rev. D

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“…However, the observations at present allow slight phantom values for the EoS parameter, i.e., w < −1 [37,38,39,40]. In case, this is confirmed by future observations, the latter might have far reaching consequences for the fate of Universe.…”

Section: Phantom Field Correspondencementioning

confidence: 63%

Cosmology with hybrid expansion law: scalar field reconstruction of cosmic history and observational constraints

Akarsu

Kumar

Myrzakulov

et al. 2014

J. Cosmol. Astropart. Phys.

161

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Abstract. In this paper, we consider a simple form of expansion history of Universe referred to as the hybrid expansion law − a product of power-law and exponential type of functions. The ansatz by construction mimics the power-law and de Sitter cosmologies as special cases but also provides an elegant description of the transition from deceleration to cosmic acceleration. We point out the Brans-Dicke realization of the cosmic history under consideration. We construct potentials for quintessence, phantom and tachyon fields, which can give rise to the hybrid expansion law in general relativity. We investigate observational constraints on the model with hybrid expansion law applied to late time acceleration as well as to early Universe a la nucleosynthesis.

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“…The latter are justified by recent Supernovae Type Ia (SNIa) observations (Novosyadlyj et al 2012;Planck Collaboration et al 2013b;Rest et al 2013;Scolnic et al 2013;Shafer & Huterer 2014). Finally we consider three additional models with a time varying equation of state.…”

Section: The Modelsmentioning

confidence: 89%

Effects of shear and rotation on the spherical collapse model for clustering dark energy

Pace¹,

Batista²,

Popolo³

2014

Monthly Notices of the Royal Astronomical Society

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In the framework of the spherical collapse model we study the influence of shear and rotation terms for dark matter fluid in clustering dark energy models. We evaluate, for different equations of state, the effects of these terms on the linear overdensity threshold parameter, δ c , and on the virial overdensity, ∆ V . The evaluation of their effects on δ c allows us to infer the modifications occurring on the mass function. Due to ambiguities in the definition of the halo mass in the case of clustering dark energy, we consider two different situations: the first is the classical one where the mass is of the dark matter halo only, while the second one is given by the sum of the mass of dark matter and dark energy. As previously found, the spherical collapse model becomes mass dependant and the two additional terms oppose to the collapse of the perturbations, especially on galactic scales, with respect to the spherical non-rotating model, while on clusters scales the effects of shear and rotation become negligible. The values for δ c and ∆ V are higher than the standard spherical model. Regarding the effects of the additional non-linear terms on the mass function, we evaluate the number density of halos. As expected, major differences appear at high masses and redshifts. In particular, quintessence (phantom) models predict more (less) objects with respect to the ΛCDM model and the mass correction due to the contribution of the dark energy component has negligible effects on the overall number of structures.

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Do the cosmological observational data prefer phantom dark energy?

Cited by 57 publications

References 62 publications

Dynamics of cosmological scalar fields

Dynamics of cosmological scalar fields

Cosmology with hybrid expansion law: scalar field reconstruction of cosmic history and observational constraints

Effects of shear and rotation on the spherical collapse model for clustering dark energy

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