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Related papers: Quintom model with O($N$) symmetry

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We examine the behavior of dark energy models in the plane defined by w (the equation of state parameter for the dark energy) and w' (the derivative of w with respect to the logarithm of the scale factor). For non-phantom barotropic fluids…

Astrophysics · Physics 2009-11-13 Robert J. Scherrer

We propose a new quintessence scenario in the brane cosmology, assuming that a quintessence field $Q$ is confined in our 3-dimensional brane world. With a potential $V(Q)= \mu^{\alpha+4} Q^{-\alpha}~(\alpha\geq 2)$, we find that the density…

Astrophysics · Physics 2009-10-31 Kei-ichi Maeda

In the present work, we investigate the universe dominated by quintom or hessence energies in Loop Quantum Cosmology (LQC). Interestingly enough, we find that there are some stable attractors in these two cases. In the case of quintom, all…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Hao Wei , Shuang Nan Zhang

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

Recently, the observed equation of state for dark energy appears to favor values below $-1$. The tendency implies that the nature of dark energy may be quite different from that of the cosmological constant. In view of the adjustment on the…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-13 Yu-Ping Teng , Wolung Lee , Kin-Wang Ng

We propose a new non-minimally coupled quintessence model to account for the late-time dark energy dynamics indicated by recent DESI measurements. Within this framework, the quintessence density begins to decrease only when it starts to…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-10 Jia-Qi Wang , Rong-Gen Cai , Zong-Kuan Guo , Yun-He Li , Shao-Jiang Wang , Xin Zhang

Recent observations suggest that the accelerated expansion of the Universe at late times is caused by a temporally changing dark energy component, rather than the constant one in the standard $\Lambda$CDM scenario. In this context…

General Relativity and Quantum Cosmology · Physics 2025-11-05 Artur Alho , Elsa Bernholm , Claes Uggla

In this article, we investigate a coupled phantom dark-energy cosmological model in which the coupling term between a phantom scalar field with an exponential potential and a pressureless dark-matter fluid is motivated by the warm…

General Relativity and Quantum Cosmology · Physics 2024-08-21 Sudip Halder , Supriya Pan , Paulo M. Sá , Tapan Saha

We explore a cyclic universe due to phantom and quintessence fields. We find that, in every cycle of the evolution of the universe, the phantom dominates the cosmic early history and quintessence dominates the cosmic far future. In this…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-02 Changjun Gao , Youjun Lu , You-Gen Shen

We constrain the parameters of dynamical dark energy in the form of a classical scalar field with barotropic equation of state jointly with other cosmological parameters using various combined datasets including the CMB power spectra from…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Olga Sergijenko , Bohdan Novosyadlyj

Recently, there has been considerable debate regarding potential evidence for the dynamical nature of dark energy (DE), particularly in light of Baryon Acoustic Oscillations (BAO) measurements released by DESI survey. In this work, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-18 Mateus Scherer , Miguel A. Sabogal , Rafael C. Nunes , Antonio De Felice

We present strong evidence for dynamical dark energy that challenges the standard $\Lambda$CDM model. Several dark energy scenarios are explored, including $\omega_0\omega_a$CDM, logarithmic, exponential, JBP, and BA parameterizations,…

General Relativity and Quantum Cosmology · Physics 2025-11-18 Himanshu Chaudhary , Salvatore Capozziello , Subhrat Praharaj , Shibesh Kumar Jas Pacif , G. Mustafa

Observations of high-redshift supernovae indicate that the universe is accelerating at the present stage, and we refer to the cause for this cosmic acceleration as ``dark energy''. In particular, the analysis of current data of type Ia…

Astrophysics · Physics 2008-11-26 Jingfei Zhang , Xin Zhang , Hongya Liu

We confront two types of phantom dark energy potential with observational data. The models we consider are the power-law potential, $V\propto {\phi}^{\mu}$, and the exponential potential, $V\propto \exp({\lambda}{\phi}/{M_P})$. We fit the…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-03 Pao-Yu Wang , Chien-Wen Chen , Pisin Chen

The recently released data of DESI DR2 favors a dynamical dark energy theory, with the equation of state crossing the cosmological constant boundary $w=-1$. In this paper, we briefly review quintom cosmology, especially the quintom bounce.…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-27 Tao-tao Qiu , Yifu Cai , Yang Liu , Si-Yu Li , Jarah Evslin , Xinmin Zhang

We derive two field theory models of interacting dark energy, one in which dark energy is associated with the quintessence and another in which it is associated with the tachyon. In both, instead of choosing arbitrarily the potential of…

General Relativity and Quantum Cosmology · Physics 2020-07-10 Sandro M. R. Micheletti

We consider the emergent universe scenario supported by a chiral cosmological model with two interacting dark sector fields: phantom and canonical. We investigate the general properties of the evolution of the kinetic and potential energies…

General Relativity and Quantum Cosmology · Physics 2013-12-09 A. Beesham , S. V. Chervon , S. D. Maharaj , A. S. Kubasov

Various cosmological models in frames of $F(T)$ gravity are considered. The general scheme of constructing effective dark energy models with various evolution is presented. It is showed that these models in principle are compatible with…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Artyom V. Astashenok

We propose a cosmological model that makes a significant step toward solving the coincidence problem of the near similarity at the present of the dark energy and dark matter components. Our cosmology has the following properties: a) among…

Astrophysics · Physics 2008-11-26 Luca Amendola , Domenico Tocchini-Valentini

Braneworld models of dark energy are examined in the light of observations of high redshift type Ia supernovae. Braneworld models admit several novel and even exotic possibilities which include: (i) The effective equation of state of dark…

Astrophysics · Physics 2007-05-23 Ujjaini Alam , Varun Sahni