Related papers: A String-Inspired Quintom Model Of Dark Energy
In this paper, we study the effects of an interaction between dark matter and dark energy through a two scalar field model with a potential $V(\phi,\chi)=e^{-\lambda\phi}P(\phi,\chi)$, where $P(\phi,\chi)$ is a polynomial. We show that the…
An oscillating scalar field as a quintessence model for dark energy is proposed. The case of a power-law potential is particularly intriguing and is the focus of the present article. In this model the equation of state w_{OQ} of dark energy…
New constraints on the expansion rate of the Universe seem to favor evolving dark energy in the form of thawing quintessence models, i.e., models for which a canonical, minimally coupled scalar field has, at late times, begun to evolve away…
The cosmological evolution of a quintessence-like scalar field, phi, coupled to matter and gauge fields leads to effective modifications of the coupling constants and particle masses over time. We analyze a class of models where the scalar…
Most parameterizations of the dark energy equation of state do not reflect realistic underlying physical models. Here, we develop a relatively simple description of dark energy based on the dynamics of a scalar field which is exact in the…
Observations from DESI DR2 are challenging the $\Lambda$CDM paradigm by suggesting that the equation-of-state parameter of dark energy evolves across $w = -1$, a phenomenon known as the Quintom scenario. Inspired by this development, we…
If dark energy is a form of quintessence driven by a scalar field $\phi$ evolving down a monotonically decreasing potential $V(\phi)$ that passes sufficiently below zero, the universe is destined to undergo a series of smooth transitions.…
A light scalar field framework of dark energy, sometimes referred to as quintessence, introduces a fifth force between normal matter objects. Screening mechanisms, such as the chameleon model, allow the scalar field to be almost massless on…
We present evidence that the simplest particle-physics scalar-field models of dynamical dark energy can be separated into distinct behaviors based on the acceleration or deceleration of the field as it evolves down its potential towards a…
We investigate a dark energy scenario in which a canonical scalar field $\phi$ is coupled to the four velocity $u_{c}^{\mu}$ of cold dark matter (CDM) through a derivative interaction $u_{c}^{\mu} \partial_{\mu} \phi$. The coupling is…
In this paper, we study the possibility of building two-field models of dark energy with equation of state across -1. Specifically we will consider two classes of models: one consists of two scalar fields (Quintessence+Phantom) and another…
This work is a review of the last results of research on the Scalar Field Dark Matter model of the Universe at cosmological and at galactic level. We present the complete solution to the scalar field cosmological scenario in which the dark…
We study the dynamics of dark energy in the presence of a 2-form field coupled to a canonical scalar field $\phi$. We consider the coupling proportional to $e^{-\mu \phi/M_{\rm pl}} H_{\alpha \beta \gamma}H^{\alpha \beta \gamma}$ and the…
We propose a new UV-complete dark energy model which is \underbar{\it neither} a cosmological constant nor a slowly rolling scalar field. Our dark energy is the flux of a top form in a hidden sector gauge theory similar to QCD. The top form…
Rolling tachyon field models are among the candidates suggested as explanations for the recent acceleration of the Universe. In these models the field is expected to interact with gauge fields and lead to variations of the fine-structure…
We explore the possibility that a scalar field with appropriate Lagrangian can mimic a perfect fluid with an affine barotropic equation of state. The latter can be thought of as a generic cosmological dark component evolving as an effective…
Within this work, we propose a new generalised quintom dark energy model in the teleparallel alternative of general relativity theory, by considering a non-minimal coupling between the scalar fields of a quintom model with the scalar…
The class of Chaplygin gas models regarded as a candidate of dark energy can be realized by a scalar field, which could drive the variation of the fine structure constant $\alpha$ during the cosmic time. This phenomenon has been observed…
We consider different classes of scalar field models including quintessence, and tachyon scalar fields with a variety of generic potential belonging to thawing type. Assuming the scalar field is initially frozen at $w=-1$, we evolve the…
Cosmological scaling solutions, which give rise to a scalar-field density proportional to a background fluid density during radiation and matter eras, are attractive to alleviate the energy scale problem of dark energy. In the presence of…