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Related papers: QCD modified ghost scalar field dark energy models

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In modern cosmology, the curiosity of ultimately understanding the nature of the dark energy controlling the recent acceleration of the Universe motivates us to explore its properties by using some novel approaches. In this work, to explore…

General Relativity and Quantum Cosmology · Physics 2023-12-19 Sanjay Mandal , Sneha Pradhan , P. K. Sahoo , Tiberiu Harko

Observations have confirmed the accelerated expansion of the universe. The accelerated expansion can be modelled by invoking a cosmological constant or a dynamical model of dark energy. A key difference between these models is that the…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-13 Manvendra Pratap Rajvanshi , Jasjeet Singh Bagla

Despite the significant accomplishments of general relativity, numerous unresolved issues persist in our understanding of the cosmos. One of the most perplexing challenges is the ongoing accelerated expansion of the Universe, which…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-22 M. Koussour , N. Myrzakulov , Alnadhief H. A. Alfedeel , Amare Abebe

In this work, we explore dark energy models, mainly ghost, generalized ghost, and generalized ghost pilgrim dark energy models within the framework of fractal cosmology. To obtain solutions for the field equations, we employ a…

General Relativity and Quantum Cosmology · Physics 2024-12-20 S. R. Bhoyar , Yash B. Ingole , A. P. Kale

We consider a model where both dark energy and dark matter originate from the coupling of a scalar field with a non-conventional kinetic term to, both, a metric measure and a non-metric measure. An interacting dark energy/dark matter…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Stefano Ansoldi , Eduardo I. Guendelman

When recent observational evidence and the GR+FRW+CDM model are combined we obtain the result that the Universe is accelerating, where the acceleration is due to some not-yet-understood "dark sector". There has been a considerable number of…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-17 Jonathan A. Pearson

In this paper we review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating Universe. In particular we discuss the arguments for and recent progress made towards…

High Energy Physics - Theory · Physics 2008-11-26 Edmund J. Copeland , M. Sami , Shinji Tsujikawa

The problem of dark energy can be roughly stated as the proposition and validation of a cosmological model that can explain the phenomenon of the accelerated expansion of the Universe. This problem is an open discussion topic in modern…

General Relativity and Quantum Cosmology · Physics 2014-12-19 Genly Leon

We investigate in this paper the cosmological evolution of a dark energy model with two scalar fields where one of the scalar has canonical kinetic energy and another scalar has negative kinetic energy term. For such a system with…

Astrophysics · Physics 2007-05-23 Zong-Kuan Guo , Yun-Song Piao , Xinmin Zhang , Yuan-Zhong Zhang

We propose a novel coupled dark energy model which is assumed to occur as a q-deformed scalar field and investigate whether it will provide an expanding universe phase. We consider the q-deformed dark energy as coupled to dark matter…

General Relativity and Quantum Cosmology · Physics 2016-12-09 Emre Dil

The dynamical aspect of accelerating cosmological model has been studied in this paper in the context of modified symmetric teleparallel gravity, the $f(Q)$ gravity. Initially, we have derived the dynamical parameters for two well known…

General Relativity and Quantum Cosmology · Physics 2023-07-18 S. A. Narawade , Shashank P. Singh , B. Mishra

In this paper, we consider a recently proposed model of Dark Energy (DE) know as Modified Holographic Ricci DE (MHRDE) (which is function of the Hubble parameter and its first derivative with respect to the cosmic time $t$) in the light of…

General Physics · Physics 2017-05-31 Antonio Pasqua , Surajit Chattopadhyay , Iuliia Khomenko

Many candidate models for dark energy are based on the existence of a classical scalar field. In the context of Quantum Field Theory (QFT), we briefly discus the condensation of such a field from a light quantum scalar field produced by…

High Energy Physics - Phenomenology · Physics 2011-12-19 Houri Ziaeepour

Major observational efforts in the coming decade are designed to probe the equation of state of dark energy. Measuring a deviation of the equation-of-state parameter w from -1 would indicate a dark energy that cannot be represented solely…

Astrophysics · Physics 2009-03-12 Alan Cooney , Simon DeDeo , Dimitrios Psaltis

The present work reports a reconstruction scheme for f(T) gravity based on QCD ghost dark energy. Two models of f(T) have been generated and the pressure and density contributions due to torsion have been reconstructed. Two realistic models…

General Relativity and Quantum Cosmology · Physics 2014-05-14 Surajit Chattopadhyay

Cosmological tests to distinguish between dark energy (DE) and modifications to gravity are a promising route to obtain clues on the origin of cosmic acceleration. We study here the robustness of these tests to the presence of DE density,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Jason Dossett , Mustapha Ishak

We numerically and analytically explore the background cosmological dynamics of multifield dark energy with highly nongeodesic or "spinning" field-space trajectories. These extensions of standard single-field quintessence possess appealing…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-25 Johannes R. Eskilt , Yashar Akrami , Adam R. Solomon , Valeri Vardanyan

According to the thermodynamics-gravity conjecture, any modification to the entropy expression leads to the modified cosmological field equations. Based on this, we investigate the cosmological consequences of the modified Friedmann…

General Relativity and Quantum Cosmology · Physics 2024-05-24 Esmaeil Ebrahimi , Ahmad Sheykhi

We investigate cosmological perturbations of f(G) gravity in the presence of a scalar field. Using the 1 + 3 covariant formalism, we present the energy overdensity perturbation equations responsible for large scale structure formation.…

General Relativity and Quantum Cosmology · Physics 2023-12-27 Albert Munyeshyaka , Joseph Ntahompagaze , Tom Mutabazi , Manasse. R Mbonye

While in the standard cosmological model the accelerated expansion of the Universe is explained by invoking the presence of the cosmological constant term, it is still unclear the true origin of this stunning observational fact. It is…

General Relativity and Quantum Cosmology · Physics 2015-10-07 Mohammad Malekjani , Tayebe Naderi , Francesco Pace