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1.
Purely kinetic k-essence models in which the Lagrangian contains only a kinetic factor and does not depend explicitly on the field itself are considered, and a theoretical constraint is obtained: Fx -= F0a^-3. Under this theoretical constraint, we discuss a kind of purely κ-essence with form F(X) = -(1 + 2X^n)^1/2n, which can be considered as the generalized tachyon field, and find that this kind of κ-essence is not likely a candidate of dark energy to describe the present accelerated expansion of the Universe. This is contrary to a previous suggestion that κ-essence with such a form may be used to describe phantom cosmologies. 相似文献
2.
Zhiqi Huang 《理论物理通讯》2022,74(9):95404
A broad class of dark energy models can be written in the form of k-essence, whose Lagrangian density is a two-variable function of a scalar field φ and its kinetic energy $X\equiv \tfrac{1}{2}{\partial }^{\mu }\phi {\partial }_{\mu }\phi $ . In the thawing scenario, the scalar field becomes dynamic only when the Hubble friction drops below its mass scale in the late Universe. Thawing k-essence dark energy models can be randomly sampled by generating the Taylor expansion coefficients of its Lagrangian density from random matrices [Huang Z 2021 Phys. Rev. D 104 103533]. Reference [Huang Z 2021 Phys. Rev. D 104 103533] points out that the non-uniform distribution of the effective equation of state parameters (w0, wa) of the thawing k-essence model can be used to improve the statistics of model selection. The present work studies the statistics of thawing k-essence in a more general framework that is Parameterized by the Age of the Universe (PAge) [Huang Z 2020 Astrophys. J. Lett. 892 L28]. For fixed matter fraction Ωm, the random thawing k-essence models cluster in a narrow band in the PAge parameter space, providing a strong theoretical prior. We simulate cosmic shear power spectrum data for the Chinese Space Station Telescope optical survey, and compare the fisher forecast with and without the theoretical prior of thawing k-essence. For an optimal tomography binning scheme, the theoretical prior improves the figure of merit in PAge space by a factor of 3.3. 相似文献
3.
4.
Olga Razina Yerlan Myrzakulov Nurzhan Serikbayev Gulgasyl Nugmanova Ratbay Myrzakulov 《Central European Journal of Physics》2012,10(1):47-50
In this paper, we have considered the g-essence and its particular cases, k-essence and f-essence, within the framework of
the Einstein-Cartan theory. We have shown that a single fermionic field can give rise to the accelerated expansion within
the Einstein-Cartan theory. The exact analytical solution of the Einstein-Cartan-Dirac equations is found. This solution describes
the accelerated expansion of the Universe with the equation of state parameter w = −1 as in the case of ΛCDM model. 相似文献
5.
M. Sharif K. Yesmakhanova S. Rani R. Myrzakulov 《The European Physical Journal C - Particles and Fields》2012,72(7):1-8
This paper is devoted to the investigation of the modified Chaplygin gas model in the context of solvable k-essence cosmologies. For this purpose, we construct equations of state parameter of this model for some particular values of the parameter n. The graphical behavior of these equations are also discussed by using power law form of scalar field. The relationship between k-essence and the modified Chaplygin gas model shows viable results in the dark energy scenario. We conclude that the universe behaves as a cosmological constant, quintessence phase or phantom phase depending upon n. 相似文献
6.
We demonstrate that if k-essence can solve the coincidence problem and play the role of dark energy in the Universe, the fluctuations of the field have to propagate superluminally at some stage. We argue that this implies that successful k-essence models violate causality. It is not possible to define a time ordered succession of events in a Lorentz invariant way. Therefore, k-essence cannot arise as a low energy effective field theory of a causal, consistent high energy theory. 相似文献
7.
Ratbay Myrzakulov 《General Relativity and Gravitation》2012,44(12):3059-3080
Modified teleparallel gravity theory with the torsion scalar has recently gained a lot of attention as a possible candidate of dark energy. We perform a thorough reconstruction analysis on the so-called $F(T)$ models, where $F(T)$ is some general function of the torsion term. We derive conditions for the equivalence between of $F(T)$ models with purely kinetic k-essence. We present a new class models of $F(T)$ gravity and k-essence. 相似文献
8.
We assume generalized ghost Pilgrim dark energy (GGPDE) model in the presence of cold dark matter in flat FRW universe. With suitable choice of interaction term between GGPDE and cold dark matter, we investigate the nature of equation of state parameter for GGPDE. Also, we investigate the natures of dynamical scalar field models (such as quintessence, tachyon, k-essence, and dilaton dark energy) and concerned potentials through the correspondence phenomenon between GGPDE and these models. 相似文献
9.
In this work, we study a new kind of dark energy (DE), which is named as "Yang-Mills condensate" (YMC). We study the stability and wde-w'de analysis of YMC DE model. Then we correspond it with quintessence, k-essence, tachyon, phantom, dilaton, DBI-essence and hessence scalar field models of DE in FRW spacetime to reconstruct potentials as well as the dynamics for these scalar fields for describing the acceleration of the universe. We also analyze the models in graphically to interpret the nature of the scalar fields and corresponding potentials. 相似文献
10.
A new, physically motivated, basis set expansion method for solving quantum eigenvalue problems with competing interaction potentials is presented. In contrast to the usual dissection of the potential energy into unperturbed and perturbing terms, we divide the kinetic energy into partial terms by modifying the mass factor. The partition scheme results in partial kinetic energies with their effective mass factors. By distributing each partial kinetic energy to a respective potential energy to form a subsystem, the total Hamiltonian is written as the sum of subsystem Hamiltonians. Using a linear combination of the subsystem wave-functions to represent the system wave-function we obtain a set of coupled equations for the expansion coefficients, by solving these energies and wave-functions can be obtained. We demonstrate the solution scheme with a standard model system: a confined harmonic oscillator in a one-dimensional box. With only a few (less than ten) basis functions from each subsystem, we can reproduce the exact solutions very accurately, thus showing the applicability of this method. 相似文献
11.
《理论物理通讯》2015,(11)
We assume generalized ghost Pilgrim dark energy(GGPDE) model in the presence of cold dark matter in flat FRW universe.With suitable choice of interaction term between GGPDE and cold dark matter,we investigate the nature of equation of state parameter for GGPDE.Also,we investigate the natures of dynamical scalar field models(such as quintessence,tachyon,k-essence,and dilaton dark energy) and concerned potentials through the correspondence phenomenon between GGPDE and these models. 相似文献
12.
P. Y. Tsyba I. I. Kulnazarov K. K. Yerzhanov R. Myrzakulov 《International Journal of Theoretical Physics》2011,50(6):1876-1886
In this paper, we consider three types of k-essence. These k-essence models were presented in the parametric forms. The exact
analytical solutions of the corresponding equations of motion are found. It is shown that these k-essence models for the presented
solutions can give rise to cosmic acceleration. 相似文献
13.
Here, we investigate the cosmological implications of Holographic Dark Energy (HDE) in the DGP braneworld model of the universe.
Taking HDE in DGP braneworld, we investigate the model of non-interacting dark energy and derive its equation of state. Subsequently,
we study the correspondence between k-essence, tachyon, dilaton, hessence and DBI-essence dark energy with the non-interacting
HDE in a flat DGP braneworld and reconstruct the corresponding scalar potentials which describe the dynamics of the scalar
fields. Also we study the correspondence between above mentioned scalar potentials and effective dark energy coming from DGP
braneworld in the absence of HDE and in this situation, the potentials are reconstructed. 相似文献
14.
We show that the most general dark energy model that possesses a scaling solution ρ?∝an is the k-essence model, which includes both of the quintessence and tachyon models. The exact scaling solutions are then derived. The potential that gives the tracking solution in which dark energy exactly tracks the background matter field is the inverse squared potential. The quintessence field with exponential potential can be obtained from the k-essence field with the inverse squared potential. We also find the fixed points and study their main properties, whereby the scalar field dominant fixed point is identified. 相似文献
15.
In this work, we consider a non-flat universe in the framework of fractal cosmology. We have investigated the co-existence of different kinds of dark energy models such as tachyonic field, DBI-essence, hessence, k-essence, dilaton, quintessence with the modified Chaplygin gas (MCG) in fractal universe and obtained the statefinder parameters. The natures of the scalar fields and the concerned potentials have been analyzed by the correspondence scenario in the fractal universe. 相似文献
16.
Jyotirmay Das Mandal Ujjal Debnath 《International Journal of Theoretical Physics》2017,56(8):2413-2422
In this work, we have tried to find out similarities between various available models of scalar field dark energies (e.g., quintessence, k-essence, tachyon, phantom, quintom, dilatonic dark energy, etc). We have defined an equivalence relation from elementary set theory between scalar field models of dark energies and used fundamental ideas from linear algebra to set up our model. Consequently, we have obtained mutually disjoint subsets of scalar field dark energies with similar properties and discussed our observation. 相似文献
17.
Rubén Cordero Eduardo L. González Alfonso Queijeiro 《The European Physical Journal C - Particles and Fields》2017,77(6):413
We investigate the physical properties of a purely kinetic k-essence model with an equation of state motivated in superconducting membranes. We compute the equation of state parameter w and discuss its physical evolution via a nonlinear equation of state. Using the adiabatic speed of sound and energy density, we restrict the range of parameters of the model in order to have an acceptable physical behavior. We study the evolution of the scale factor and address the question of the possible existence of finite-time future singularities. Furthermore, we analyze the evolution of the luminosity distance \(\mathrm{d}_{L}\) with redshift z by comparing (normalizing) it with the \(\Lambda \)CDM model. Since the equation of state parameter is z-dependent the evolution of the luminosity distance is also analyzed using the Alcock–Paczyński test. 相似文献
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19.
Víctor H. Cárdenas Norman Cruz Sebastian Muñoz J. R. Villanueva 《The European Physical Journal C - Particles and Fields》2018,78(7):591
In this paper the Lagrangian density of a purely kinetic k-essence model that describes the behavior of dark energy described by four parameterized equations of state proposed by Cooray and Huterer (Astrophys J 513:L95, 1999), Zhang and Wu (Mod Phys Lett A 27:1250030, 2012), Linder (Phys Rev Lett 90:091301, 2003), Efstathiou (Mon Not R Astron Soc 310:842, 2000), and Feng and Lu (J Cosmol Astropart Phys 1111:34, 2011) has been reconstructed. This reconstruction is performed using the method outlined by de Putter and Linder (Astropart Phys 28:263, 2007), which makes it possible to solve the equations that relate the Lagrangian density of the k-essence with the given equation of state (EoS) numerically. Finally, we discuss the observational constraints for the models based on 1049 SNIa data points from the Pantheon data set compiled by Scolnic et al. (Astrophys J 859(2):101, 2018) 相似文献
20.
Summary Reasonable surface energies and very accurate surface dipole barrier and work function for a semi-infinite jellium are calculated
from a simple model of the density. The model was proposed by Smith and contains one universal parameter. In the Kohn-Sham
energy functional, the kinetic energy is approximated by its simple gradient expansion including a fourth-order term. The
exchange and correlation are treated within the local-density approximation. Using the simple gradient, the energy is minimized
with respect to the universal parameter of the density. The parameter which minimizes the energy is used to calculate the
surface dipole barrier and the work function. A comparison was made with the Lang and Kohn results and with the Ma and Sahni
results. 相似文献