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We consider generic models of quintessence and we investigate the influence of massive neutrino matter with field-dependent masses on the matter power spectrum. In case of minimally coupled neutrino matter, we examine the effect in tracker…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-28 Chao-Qiang Geng , Chung-Chi Lee , R. Myrzakulov , M. Sami , Emmanuel N. Saridakis

In this brief review, we examine the theoretical consistency and viability of phantom dark energy. Almost all data sets from cosmological probes are compatible with dark energy of the phantom variety (i.e., equation-of-state parameter…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-26 Kevin J. Ludwick

Soft cosmology is an extension of standard cosmology allowing for a scale-dependent equation-of-state (EoS) parameter in the dark sectors, which is one of the properties of soft materials in condensed-matter physics, that may arise either…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-12 Emmanuel N. Saridakis , Weiqiang Yang , Supriya Pan , Fotios K. Anagnostopoulos , Spyros Basilakos

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…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-05 J. Betz , J. Manley , E. M. Wright , D. Grin , S. Singh

In this work, we consider the cosmological constraints on the interacting dark energy models. We generalize the models considered previously by Guo {\it et al.}, Costa and Alcaniz, and try to discuss two general types of models: type I…

General Relativity and Quantum Cosmology · Physics 2010-07-21 Hao Wei

Using the constant-roll approach, DBI inflationary scenario will be studied and it is sought to compare the result with observational data. By considering the cosmological perturbations of the model, it is realized that some extra terms…

General Relativity and Quantum Cosmology · Physics 2020-05-12 Abolhassan Mohammadi , Tayeb Golanbari , Khaled Saaidi

We consider a field theory model of coupled dark energy which treats dark energy as a three-form field and dark matter as a spinor field. By assuming the effective mass of dark matter as a power-law function of the three-form field and…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-04 YanHong Yao , YangJie Yan , XinHe Meng

New dark energy models in anisotropic Bianchi type-I (B-I) space-time with variable EoS parameter and constant deceleration parameter have been investigated in the present paper. The Einstein's field equations have been solved by applying a…

General Physics · Physics 2011-07-15 Anirudh Pradhan , H. Amirhashchi , Bijan Saha

In this paper we have explored the consequences of a model of dark energy with its energy density varying exponentially with the scale factor. We first consider the model with $ \rho_{\phi} \propto e^{\kappa a} $, where $\kappa $ is a…

Astrophysics · Physics 2009-11-13 Sanil Unnikrishnan , T. R. Seshadri

In this paper, we have presented a power law cosmological model and its dynamical system analysis in $f(T,\phi)$ gravity, where $T$ is the torsion scalar and $\phi$ is the canonical scalar field. The two well-motivated forms of the…

General Relativity and Quantum Cosmology · Physics 2025-01-10 S. A. Kadam , Ananya Sahu , S. K. Tripathy , B. Mishra

In this work we explore the possibility of incorporating particle physics motivated scalar fields to the dark matter cosmological model. In this landscape, we consider the classical complex scalar field in a certain region in the parameter…

In the presence of a strong magnetic field, the effective action of a composite scalar field in an scalar O(N) model is derived using two different methods. First, in the framework of worldline formalism, the 1PI n-point vertex function for…

High Energy Physics - Theory · Physics 2008-11-26 Amir Jafari Salim , Neda Sadooghi

We study the dynamics of the scalar tensor cosmological model in the presence of tachyon field. In an alternative approach, in two exponential and power law form of the scalar field functions in the model, field equations are solved by…

General Relativity and Quantum Cosmology · Physics 2011-11-22 H. Farajollahi , A. Salehi , A. Shahabi

The chameleon scalar field is a matter-coupled dark energy candidate whose nonlinear self-interaction partially screens its fifth force at laboratory scales. Nevertheless, small-scale experiments such as the torsion pendulum can provide…

High Energy Physics - Phenomenology · Physics 2013-05-30 Amol Upadhye

We study the evolution of spatial curvature for thawing class of dark energy models. We examine the evolution of the equation of state parameter, $w_\phi$, as a function of the scale factor $a$, for the case in which the scalar field $\phi$…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 Sergio del Campo , Victor H. Cardenas , Ramon Herrera

In this talk, I have discussed the implications of a multi-component nature of cosmic Dark Matter for the observational bounds on possible long-range fifth-forces mediated by a Dark Energy scalar field. By assuming a simple internal…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-19 Marco Baldi

In dark energy models of scalar-field coupled to a barotropic perfect fluid, the existence of cosmological scaling solutions restricts the Lagrangian of the field $\vp$ to $p=X g(Xe^{\lambda \vp})$, where $X=-g^{\mu\nu} \partial_\mu \vp…

High Energy Physics - Theory · Physics 2009-02-25 Burin Gumjudpai , Tapan Naskar , M. Sami , Shinji Tsujikawa

The reconstruction of a (non)canonical scalar field Lagrangian from the dark energy Equation of State (EoS) parameter is studied, where it is shown that any EoS parametrization can be well reconstructed in terms of scalar fields. Several…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Iker Leanizbarrutia , Diego Sáez-Gómez

We demonstrate that massive fields, such as dark matter, can directly produce a cosmological evolution of the fundamental constants of Nature. We show that a scalar or pseudoscalar (axion-like) dark matter field $\phi$, which forms a…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-18 Y. V. Stadnik , V. V. Flambaum

We investigate the behaviour of the skewness parameters for an anisotropic universe in the framework of General Relativity. Non interacting dark energy is considered in presence of electromagnetic field. A time varying deceleration…

General Physics · Physics 2022-07-19 B. Mishra , Pratik P Ray , S. K. Tripathy , Kazuharu Bamba
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