相关论文: K-essential Phantom Energy: Doomsday around the Co…
Although generalized Chaplygin phantom models do not show any big rip singularities, we investigated k-essence models together with noncanonical kinetic energy for which there might be a big rip future singularity in the phantom region. We…
We restrict purely kinetic k-essence. Assuming the equation of state is a power law of the kinetic energy: $w=w_0X^{\alpha}$, to obtain accelerated phases, we must have $\alpha>0$ as one of necessary conditions, constrained from the…
A generalized parameterization $w_\beta(z)$ for the dark energy equation of state (EoS) is proposed and some of its cosmological consequences are investigated. We show that in the limit of the characteristic dimensionless parameter $\beta…
The smallness of the variation rate of the hamiltonian matrix elements compared to the (square of the) energy spectrum gap is usually believed to be the key parameter for a quantum adiabatic evolution. However it is only perturbatively…
A phenomenological model is described for Cosmic Microwave Background Radiation (CMBR) evolution with dark energy an essential ingredient in the form of a $k-$essence scalar field. The following features of this evolution can be…
We develop here a relatively simple description of dark energy based on the dynamics of non-minimally coupled to gravity phantom scalar field which, in limit, corresponds to cosmological constant. The dark energy equation of state, obtained…
In spite of its rather weird properties which include violation of the dominant-energy condition, the requirement of superluminal sound speed and increasing vacuum-energy density, phantom energy has recently attracted a lot of scientific…
In the particular configuration of the scalar field K-essence in the Wheeler-DeWitt quantum equation, for some age in the Bianchi type I anisotropic cosmological model, a fractional differential equation for the scalar field arises…
The $\eta^\prime$ transition form factor is reanalyzed in view of the recent BESIII first observation of the Dalitz decay $\eta^\prime\to\gamma e^+e^-$ in both space- and time-like regions at low and intermediate energies using the Pad\'e…
A classical-kind phase-space formalism is developed to address the tiny intrinsic dynamical deviation from what is predicted by Wilczek-Zee theorem during quantum adiabatic evolution on degeneracy levels. In this formalism, the Hilbert…
The \eta and \eta' transition form factors in the space-like region are analyzed at low and intermediate energies in a model-independent way through the use of rational approximants. The slope and curvature parameters of the form factors as…
Using a particular form of the quantum K-essence scalar field, we show that in the quantum formalism, a fractional differential equation in the scalar field variable, for some epochs in the Friedmann-Lema\^itre-Robertson-Walker (FLRW) model…
The effects of phase space deformations on Kalutza-Klein cosmology are studied. The deformation is introduced by modifying the symplectic structure of the minisuperspace variables. In the deformed model, we find an accelerating scale factor…
We construct the non-canonical kinetic term of a k-essence field directly from the effective equation of state function $w_k(z)$, which describes the properties of the dark energy. Adopting the usual parametrizations of equation of state we…
A lagrangian for the $k-$ essence field is set up with canonical kinetic terms and incorporating the scaling relation of [1]. There are two degrees of freedom, {\it viz.},$q(t)= ln\enskip a(t)$ ($a(t)$ is the scale factor) and the scalar…
On basis of modification of Einstein's gravitational equations by adding the term $f(R)\propto \beta R^n$, a geometric model of quintessence is proposed. The evolution equation for the scale factor $a$ of the Universe is analyzed for the…
This paper uses the beta function formalism to extend the analysis of quintessence cosmological parameters to the logarithmic and exponential dark energy potentials. The previous paper (Thompson 2018) demonstrated the formalism using power…
The unique properties of central potential of the form $-\beta e^{-r}r^{\gamma}$ were studied using the recently developed critical parameter technique. The particular cases of $\gamma=0$ and $\gamma=-1$ yield, respectively, the exponential…
We present a method of determining weak phase \gamma in the Cabibbo-Kobayashi-Maskawa matrix from decays B->\eta K, \eta' K$ alone. Given a large ratio between color-suppressed and color-allowed tree diagrams extracted from global \pi\pi(K)…
Evolution of the scale factor a(t) in Friedmann models (those with zero pressure and a constant cosmological term Lambda) is well understood, and elegantly summarized in the review of Felten and Isaacman [Rev. Mod. Phys. 58, 689 (1986)].…