Related papers: Tachyonic field interacting with Scalar (Phantom) …
A detailed dynamical analysis of the tachyonic teleparallel dark energy model, in which a non-canonical scalar field (tachyon field) is non-minimally coupled to gravitation, is performed. It is found that, when the non-minimal coupling is…
A tachyon field having a negative squared-mass $-m_t^2$ can be described in terms of massless fields degenerating infinitely with respect to the helicity. The degeneracy leads symmetry breakings of space-time. This picture for the tachyon…
We study the possibility to construct an observationally viable scenario where both early Inflation and the recently detected accelerated expansion of the universe can be explained by using a single scalar field associated with the Tachyon.…
In this article we investigate and develop specific aspects of Friedmann-Robertson-Walker (FRW) scalar field cosmologies related to the interpretation that canonical and phantom scalar field sources may be interpreted as cosmological…
In this work we investigate the evolution of a Universe consisted of a scalar field, a dark matter field and non-interacting baryonic matter and radiation. The scalar field, which plays the role of dark energy, is non-minimally coupled to…
This paper is devoted to some simple approach based on general physics tools to describe the physical properties of a hypothetical particle which can be the source of dark energy in the Universe known as phantom. Phantom is characterized by…
We investigate a multi-field model of dark energy in this paper. We develop a model of dark energy with two multiple scalar fields, one we consider, is a multifield tachyon and the other is multi-field phantom tachyon scalars. We make an…
In the present work, an attempt has been made to explain the recent cosmic acceleration with two mutually interacting scalar fields, one being the Brans-Dicke scalar field and the other a quintessence scalar field. Conditions have been…
A cosmic scalar field evolving very slowly in time can account for the observed dark energy of the Universe. Unlike a cosmological constant, an evolving scalar field also has local spatial gradients due to gravity. If the scalar field has a…
A new cosmological scenario driven by a slow rolling homogeneous scalar field whose exponential potential $V(\Phi)$ has a quadratic dependence on the field $\Phi$ in addition to the standard linear term is discussed. The derived equation of…
In this work we investigate localized and extended objects for gravitating, self-interacting phantom fields. The phantom fields come from two scalar fields with a "wrong sign" (negative) kinetic energy term in the Lagrangian. This study…
A detailed comparative qualitative analysis and numerical simulation of evolution of the cosmological models based on the doublet of classical and phantom scalar fields with self-action. The 2-dimensional and 3-dimensional projections of…
It is often the case that scalar fields are produced in the early Universe in the form of coherent oscillation. These scalar fields may have huge abundances and affect the evolution of the Universe. In particular, if the lifetime is long…
Models of the universe with arbitrary (non gravitational) interaction between the components of the cosmic fluid: the phantom energy and the background, are investigated. A general form of the interaction that is inspired in scalar-tensor…
Motivated by the recent interest in phantom fields as candidates for the dark energy component, we investigate the consequences of the phantom field when is minimally coupled to gravity. In particular, the necessary (but insufficient)…
There are many different phenomenological models describing the cosmological dark energy and accelerating Universe by choosing adjustable functions. In this paper we consider a specific model of scalar tachyon field which is derived from…
In a ghost-condensate model of dark energy the combined dynamics of the scalar field and gravitation is shown to impose non-trivial restriction on the self-interaction of the scalar field. Using this restriction we show that the choice of a…
The dynamical analysis for coupled dark energy with dark matter is presented, where a complex scalar field is taken into account and it is considered in the presence of a barothropic fluid. We consider three dark energy candidates:…
The features of a homogeneous scalar field $\phi$ with classical Lagrangian $L=\phi_{;i}\phi^{;i}/2-V(\phi)$ and tachyon field Lagrangian $L=-V(\phi)\sqrt{1-\phi_{;i}\phi^{;i}}$ causing the observable accelerated expansion of the Universe…
We study the evolution of the two scalar fields entangled via a mutual interaction in an expanding spacetime. We compute the logarithmic negativity to leading order in perturbation theory and show that for lowest order in the coupling…