New holographic reconstruction of scalar-field dark-energy models in the framework of chameleon Brans–Dicke cosmology
Surajit Chattopadhyay
2
Antonio Pasqua
1
Martiros Khurshudyan
0
3
0
Department of Theoretical Physics, Yerevan State University
, 1 A. Manookian, Yerevan,
Armenia
1
Department of Physics, University of Trieste
, Via Valerio, 2, 34127 Trieste,
Italy
2
Pailan College of Management and Technology
, Bengal Pailan Park, Kolkata 700 104,
India
3
Present address: Max Planck Institute of Colloids and Interfaces, Potsdam-Golm Science Park
, Am Mhlenberg 1 OT Golm,
14476 Potsdam, Germany
Motivated by the work of Yang et al. (Mod. Phys. Lett. A 26:191, 2011), we report on a study of the new holographic dark energy (NHDE) model with energy density given by D = 342 (H 2 + H ) in the framework of chameleon Brans-Dicke cosmology. We have studied the correspondence between the quintessence, the DBI-essence, and the tachyon scalar-field models with the NHDE model in the framework of chameleon Brans-Dicke cosmology. Deriving an expression of the Hubble parameter H and, accordingly, D in the context of chameleon Brans-Dicke chameleon cosmology, we have reconstructed the potentials and dynamics for these scalar-field models. Furthermore, we have examined the stability for the obtained solutions of the crossing of the phantom divide under a quantum correction of massless conformally invariant fields, and we have seen that the quantum correction could be small when the phantom crossing occurs and the obtained solutions of the phantom crossing could be stable under the quantum correction. It has also been noted that the potential increases as the matterchameleon coupling gets stronger with the evolution of the universe. The approaches to account for the late-time cosmic acceleration, which is suggested by the two independent observational signals on distant Type Ia Supernovae (SNeIa) [13], the cosmic microwave background (CMB) temperature anisotropies measured by the WMAP and Planck satellites
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[46] and Baryon Acoustic Oscillations (BAO) [7,8], fall
into two representative categories: in the first, the concept
of dark energy is introduced in the right-hand side of the
Einstein equation in the framework of general relativity (for
good reviews see [911]), while in the second one the
lefthand side of the Einstein equation is modified, leading to a
modified gravitational theory (which is well reviewed in [12
15]). In a recent review, Bamba et al. [10] demonstrated that
both dark-energy models and modified gravity theories seem
to be in agreement with data and hence, unless higher
precision probes of the expansion rate and the growth of structure
will be available, these two rival approaches could not be
discriminated. The physical origin of dark energy (DE) is one
of the largest mysteries not only in cosmology but also in
fundamental physics [9,1619]. The cosmological constant
represents the earliest and the simplest theoretical
candidate proposed in order to explain the observational evidence
of accelerated expansion. Some tentative deviations from the
CDM model may eventually rule out an exact cosmological
constant [20,21]. A considerable number of models for DE
have been proposed up to now to explain the late-time cosmic
acceleration without the cosmological constant. Such models
include a canonical scalar field, the so-called quintessence,
a non-canonical scalar field such as phantom, tachyon scalar
field motivated by string theories, and a fluid with a
special equation of state (EoS) called a Chaplygin gas. Other
well studied candidates for DE are the k-essence, the
quintom and the agegraphic dark energy (ADE) models.
Studies on the models previously mentioned include [9,10,22
29]. There also exists a proposal known as holographic dark
energy (HDE) proposed by Li [30], following the idea that
the short distance cut-off is related to the infrared cut-off and
it was assumed in [30] that the infrared cut-off relevant to the
dark energy is the size of the event horizon. Some notable
works on HDE include [3134]. Furthermore, there exists
plethora of literature on HDE in theoretical aspects as well
as observational constraints e.g. [3537].
The equation of state (EoS) parameter, defined as wDE =
pDE/DE (where pDE and DE denote the pressure and
density of DE, respectively), is one of the most important
quantity used to describe the features of DE models. If we restrict
ourselves to four-dimensional Einsteins gravity, almost all
DE models can be classified according to the behavior of the
EoS parameter as follows [38]: (i) Cosmological constant:
w = 1; (ii) Quintessence: wQ 1; (iii) Phantom:
wP 1 and (iv) Quintom: its EoS is able to evolve across
the cosmological constant boundary. Scalar field models of
dark energy are among the most promising and best
elaborated ones to match observations of the accelerated
expansion of the Universe. The phantom-like behavior of wDE may
appear from BransDicke (BD) scalartensor gravity, from
non-standard (negative) potentials, from the non-minimal
coupling of a scalar Lagrangian with gravity, (...truncated)