Transient and late time attractor tachyon dark energy: Can we distinguish it from quintessence?

Ali, Amna; Sami, M.; Sen, Anjan A.

doi:10.1103/physrevd.79.123501

Cited by 35 publications

(33 citation statements)

References 52 publications

(31 reference statements)

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“…They showed that under the slow‐roll conditions, a scalar field with a variety of potentials V (φ) evolves in a similar fashion and one can derive a generic expression for the equation of state for all such scalar fields. Similar results were later obtained for the case of phantom (Scherrer & Sen 2008b) and tachyon scalar fields (Ali et al 2009; Sen et al 2010). It was demonstrated that under slow‐roll conditions, all of them have identical equations of state and hence cannot be distinguished, not at least at the level of background cosmology.…”

Section: Introductionsupporting

confidence: 82%

“…With the slow‐roll condition satisfied, i.e. λ i x ≪ 1, it was shown earlier that models with different potentials have an identical w ( a ) for both scalar and tachyon fields (Scherrer & Sen 2008a,b; Ali et al 2009). Although we show equations of state for some models which are more than w =−0.8 at present, these models are practically ruled out by the current observational data.…”

Section: Background Evolution For Thawing Dark Energy Modelsmentioning

confidence: 99%

“…The tachyon field is specified by the Dirac–Born–Infeld (DBI) type of action (Bergshoeff et al 2000; Garousi 2000; Kluson 2000; Sen 2002a,b; Kutasov & Niarchos 2003): In the FRW background, the pressure and energy density of the tachyon field φ are given by The equation of motion which follows from () is where H is the Hubble parameter and here prime denotes the derivative with respect to φ. Now assuming and , we can also form an autonomous system of equations involving Ω φ , γ= (1 + w ) and λ for tachyons (Ali et al 2009): …”

Section: Background Evolution For Thawing Dark Energy Modelsmentioning

confidence: 99%

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Evolution of spherical overdensity in thawing dark energy models

Devi

Sen

2011

Monthly Notices of the Royal Astronomical Society

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We study the general evolution of spherical overdensities for the thawing class of dark energy models. We model dark energy with scalar fields having canonical as well as non‐canonical kinetic energy. For the non‐canonical case, we consider models where the kinetic energy is of the Born–Infeld form. We study various potentials such as linear, inverse‐square, exponential as well as PNGB type. We also consider the case where dark energy is homogeneous as well as the case where it is inhomogeneous and virializes together with matter. Our study shows that models with a linear potential, in particular those with a Born–Infeld type kinetic term, can have a significant deviation from the ΛCDM model in terms of density contrast at the time of virialization. Although our approach is a simplified one to study the non‐linear evolution of matter overdensities inside the cluster and is not applicable to the actual physical situation, it gives some interesting insights into the non‐linear clustering of matter in the presence of the thawing class of dark energy models.

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Section: Introductionsupporting

confidence: 82%

Section: Background Evolution For Thawing Dark Energy Modelsmentioning

confidence: 99%

Section: Background Evolution For Thawing Dark Energy Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Evolution of spherical overdensity in thawing dark energy models

Devi

Sen

2011

Monthly Notices of the Royal Astronomical Society

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“…They have shown that under such conditions thawing models with variety of potentials evolve in a similar fashion and results in a unique analytic expression for the equation of state w ( z ). This result was later extended to the case of phantom models (Scherrer & Sen 2008b) and tachyon scalar field models (Ali, Sami & Sen 2009). In another work, thawing models (for both canonical and non‐canonical scalar fields) have been studied without the assumption of the slow roll condition (Sen, Sen & Sami 2010).…”

Section: Introductionmentioning

confidence: 83%

Constraining thawing quintessence

Gupta

Majumdar

Sen

2011

Monthly Notices of the Royal Astronomical Society

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We look at observational constraints on the thawing class of scalar field models proposed to explain the late‐time acceleration of the universe. Using the recently introduced ‘Statefinder hierarchy’, we compare these thawing class of models with other widely studied dark energy (and modified gravity) models to check the underlying parameter degeneracies. We put constraints on the deviations of these thawing models from the canonical Λ cold dark matter (ΛCDM) model using a large class of observational data, e.g. the Type Ia supernova (SN) data, the baryon acoustic oscillation data, the cosmic microwave background data and data from the measurements of the Hubble parameter using red‐envelope galaxies. We also forecast constraints using a simulated data set for the future Joint Dark Energy Mission (JDEM) SN survey. Our study shows that, although with current data it is difficult to distinguish different thawing models from ΛCDM, a future JDEM‐like mission would be able tell apart thawing models from ΛCDM for currently acceptable values of Ωm0.

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“…The scalar field models (such as quintessence, phantom, quintom, tachyon, K-essence, dilaton and Chaplygin) are often regarded as an effective description of an underlying theory of DE [10]. The scalar field models can alleviate the fine tuning and coincidence problems [11]. Scalar fields naturally arise in particle physics including supersymmetric field theories and string/M theory.…”

Section: Introductionmentioning

confidence: 99%

Ghost Chaplygin scalar field model of dark energy

2013

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In this work, we establish a correspondence between the interacting holographic, new agegraphic dark energy and generalized Chaplygin gas model in Bianchi type I universe. In continue, we reconstruct the potential of the scalar field which describes the generalized Chaplygin cosmology. Cosmological solutions are obtained when the kinetic energy of the phantom field is order of the anisotropy and dominates over the potential energy of the field. We investigate observational constraints on the generalized Chaplygin gas, holographic and new agegraphic dark energy models as the unification of dark matter and dark energy, by using the latest observational data. To do this we focus on observational determinations of the expansion history H(z). It is shown that the HDE model is better than the NADE and generalized Chaplygin gas models in an anisotropic universe. Then, we calculate the evolution of density perturbations in the linear regime for three models of dark energy and compare the results ΛCDM model. Finally, the analysis shows that the increase in anisotropy leads to more correspondence between the dark energy scalar field model and observational data.

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Transient and late time attractor tachyon dark energy: Can we distinguish it from quintessence?

Cited by 35 publications

References 52 publications

Evolution of spherical overdensity in thawing dark energy models

Evolution of spherical overdensity in thawing dark energy models

Constraining thawing quintessence

Ghost Chaplygin scalar field model of dark energy

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