Xin-zhou Li

Phantom with Born-Infield type Lagrangian

Recent analysis of the observation data indicates that the equation of state of the dark energy might be smaller than -1, which leads to the introduction of phantom models featured by its negative kinetic energy to account for the regime of equation of state

Born-Infeld type phantom on the brane world

w<-1

Reconstructing the equation of state of the tachyon

. In this paper, we generalize the idea to the Born-Infield type Lagrangian with negative kinetic energy term and give the condition for the potential, under which the late time attractor solution exists and also analyze a viable cosmological model in such a scheme.

Constructing dark energy models with a late time de Sitter attractor

We study the evolution of Born-Infeld-type phantom in the second Randall-Sundrum brane scenario, and find that there exists attractor solution for the potential with a maximum, which implies a cosmological constant at the late time. Especially, we discuss the BI model of constant potential without and with dust matter. In the weak tension limit of the brane, we obtain an exact solution for the BI phantom and scale factor and show that there is no big rip during the evolution of the brane.

Casimir pistons with hybrid boundary conditions

Recent progress in theoretical physics suggests that the dark energy in the universe might result from the rolling tachyon field of string theory. Measurements to SNe Ia can be helpful in reconstructing the equation of state of the rolling tachyon which is a possible candidate of dark energy. We present a numerical analysis for the evolution of the equation of state of the rolling tachyon and derive the reconstruction equations for the equation of state as well as the potential.

Latest observational constraints to the ghost dark energy model by using the Markov chain Monte Carlo approach

In this paper, we describe a way to construct a class of dark energy models that admit late time de Sitter attractor solution. In the canonical scalar and Born-Infeld scalar dark energy models, we show mathematically that a simple sufficient condition for the existence of a late time de Sitter like attractor solution is that the potentials of the scalar field have non-vanishing minimum while this condition becomes that the potentials have non-vanishing maximum for the phantom models. These attractor solutions correspond to an equation of state

THERMODYNAMIC OF THE GHOST DARK ENERGY UNIVERSE

w=-1

Cosmological perturbations and noncommutative tachyon inflation

and a cosmic density parameter

Preventing eternality in phantom inflation

\Omega_{\phi}=1

Tachyon inflationary models with exact mode functions

, which are important features for a dark energy model that can meet the current observations.