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Related papers: Theoretical Aspects of Quintom Models

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We investigate the cosmological evolution of a two-field model of dark energy where one is a dilaton field with canonical kinetic energy and the other is a phantom field with a negative kinetic energy term. A phase-plane analysis shows that…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-10 Nan Liang , ChangJun Gao , ShuangNan Zhang

We revisit a cosmological model where dark matter (DM) and dark energy (DE) follow barotropic equations of state, allowing deviations from the standard $\Lambda$CDM framework (i.e. $w_{dm} \neq 0$, $w_{de} \neq -1$), considering both flat…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-24 Dorian Araya , Cristian Castillo , Genly Leon , Juan Magaña , Angie Barr Domínguez , Miguel A. García-Aspeitia

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…

General Relativity and Quantum Cosmology · Physics 2020-12-29 Muhammad Zahid Mughal , Iftikhar Ahmad

Analyzing quantum cosmological scenarios containing one scalar field with exponential potential, we have obtained a universe model which realizes a classical dust contraction from very large scales, the initial repeller of the model, and…

General Relativity and Quantum Cosmology · Physics 2017-09-13 Samuel Colin , Nelson Pinto-Neto

Dark energy with the usually used equation of state $p=w\rho$, where $w=const<0$ is hydrodynamically unstable. To overcome this drawback we consider the cosmology of a perfect fluid with a linear equation of state of a more general form…

Astrophysics · Physics 2009-11-06 E. Babichev , V. Dokuchaev , Yu. Eroshenko

A general equation of state is considered for analysing the possible behaviors for (Early) dark energy that alleviates the Hubble parameter tension problem. By departing from the possible evolution for the (Early) dark energy density and…

General Relativity and Quantum Cosmology · Physics 2021-05-25 Shin'ichi Nojiri , Sergei D. Odintsov , Diego Saez-Chillon Gomez , German S. Sharov

I briefly review the cosmological constant problem and the issue of dark energy (or quintessence). Within the framework of quantum field theory, the vacuum expectation value of the energy momentum tensor formally diverges as $k^4$. A cutoff…

Astrophysics · Physics 2008-11-26 Varun Sahni

We examine an extension of the quintom scenario of dark energy, in which a canonical scalar field and a phantom field are coupled through a kinetic interaction. We perform a phase space analysis and show that the kinetic coupling gives rise…

High Energy Physics - Theory · Physics 2014-11-20 Emmanuel N. Saridakis , Joel M. Weller

We investigate the phase-space structure of the quintom dark energy paradigm in the framework of spatially flat and homogeneous universe. Considering arbitrary decoupled potentials, we find certain general conditions under which the phantom…

General Relativity and Quantum Cosmology · Physics 2013-02-27 Genly Leon , Yoelsy Leyva , J. Socorro

Considering the quintom model with arbitrary potential, it is shown that there always exists a solution which evolves from w > -1 region to w < -1 region. The problem is restricted to the slowly varying potentials, i.e. the slow-roll…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. Alimohammadi , H. Mohseni Sadjadi

By studying the present cosmological data, particularly on CMB, SNeIA and LSS, we find that the future fate of the universe, for simple linear models of the dark energy equation-of-state, can vary between the extremes of (I) a divergence of…

Astrophysics · Physics 2009-11-10 Paul H. Frampton

Quantum cosmology with quintom dark energy model has been investigated in the present work using symmetry analysis of the underlying physical system. In the background of the flat FLRW model quintom cosmological model has been studied using…

General Physics · Physics 2021-04-23 Sourav Dutta , Muthusamy Lakshmanan , Subenoy Chakraborty

Quintessence, a scalar field model, has been proposed to account for the acceleration of the Universe at present. We discuss how accurately quintessence models are discriminated by future cosmological surveys, which include experiments of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Yoshitaka Takeuchi , Kiyotomo Ichiki , Tomo Takahashi , Masahide Yamaguchi

In this paper, we study the possibility of model building of cyclic universe with Quintom matter in the framework of Loop Quantum Cosmology. After a general demonstration, we provide two examples, one with double-fluid and another…

High Energy Physics - Theory · Physics 2010-04-23 Hua-Hui Xiong , Taotao Qiu , Yi-Fu Cai , Xinmin Zhang

A new approach to quantum mechanics based on independence of the Continuum Hypothesis is proposed. In one-dimensional case, it is shown that the properties of the set of intermediate cardinality coincide with quantum phenomenology.

Quantum Physics · Physics 2007-05-23 O. Yaremchuk

By quantizing the background as well as the perturbations in a simple one fluid cosmological model, we show that there exists an ambiguity in the choice of relevant variables, potentially leading to incompatible observational physical…

General Relativity and Quantum Cosmology · Physics 2022-03-09 Jaime de Cabo Martin

By combining data from seven cosmic microwave background experiments (including the latest WMAP results) with large scale structure data, the Hubble parameter measurement from the Hubble Space Telescope and luminosity measurements of Type…

Astrophysics · Physics 2008-11-26 Alessandro Melchiorri , Laura Mersini , Carolina J. Odman , Mark Trodden

Dark energy cosmologies with an equation of state parameter $w$ less than -1 are often found to violate the null energy condition and show unstable behaviour. A solution to this problem may require the existence of a consistent effective…

High Energy Physics - Theory · Physics 2009-04-22 Ben M. Leith , Ishwaree P. Neupane

Assuming the Hubble parameter is a continuous and differentiable function of comoving time, we investigate necessary conditions for quintessence to phantom phase transition in quintom model. For power-law and exponential potential examples,…

General Relativity and Quantum Cosmology · Physics 2009-11-11 H. Mohseni Sadjadi , M. Alimohammadi

We investigate the restrictions on the equation-of-state parameter of phantom cosmology, due to the minimum quantum gravitational requirements. We find that for all the examined $w_\Lambda(z)$-parametrizations and for arbitrary phantom…

High Energy Physics - Theory · Physics 2014-11-18 Emmanuel N. Saridakis
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