scholarly journals Phantom field withO(N)symmetry in an exponential potential

2004 ◽  
Vol 69 (10) ◽  
Author(s):  
Xin-zhou Li ◽  
Jian-gang Hao
Open Physics ◽  
2014 ◽  
Vol 12 (12) ◽  
Author(s):  
Sami Ortakaya

AbstractThe pseudospin and spin symmetric solutions of the Dirac equation with Hulthén-type tensor interaction are obtained under multi-parameter-exponential potential (MEP) for arbitrary κ states. The energy eigenvalues and the corresponding eigenfunctions are also obtained using the parametric Nikiforov-Uvarov (NU) method. Some numerical results are also obtained for pseudospin and spin symmetry limits.


1978 ◽  
Vol 56 (10) ◽  
pp. 1358-1364 ◽  
Author(s):  
J. W. Darewych ◽  
R. Pooran

We derive bounds to the absolute value of the error that is made in variational estimates of scattering phase shifts. These bounds, like the variational estimates, are second order in 'small' quantities and are, in this respect, an improvement on similar but first-order error bounds derived previously by Bardsley, Gerjuoy, and Sukumar. The s-wave scattering by a square well potential, in the Born approximation, and by an exponential potential, using a many parameter trial function, are used to illustrate the results.


2018 ◽  
Vol 15 (12) ◽  
pp. 1850212 ◽  
Author(s):  
K. Kleidis ◽  
V. K. Oikonomou

In this paper we will study the cosmological dynamical system of an [Formula: see text] gravity in the presence of a canonical scalar field [Formula: see text] with an exponential potential by constructing the dynamical system in a way that it is rendered autonomous. This feature is controlled by a single variable [Formula: see text], which when it is constant, the dynamical system is autonomous. We focus on the [Formula: see text] case which, as we demonstrate by using a numerical analysis approach, leads to an unstable de Sitter attractor, which occurs after [Formula: see text] [Formula: see text]-foldings. This instability can be viewed as a graceful exit from inflation, which is inherent to the dynamics of de Sitter attractors.


2011 ◽  
Vol 52 (1-2) ◽  
pp. 165-170 ◽  
Author(s):  
S. Zarrinkamar ◽  
A. A. Rajabi ◽  
H. Hassanabadi

AIP Advances ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 065304 ◽  
Author(s):  
Xiongwu Wu ◽  
Bernard R. Brooks

2017 ◽  
Vol 26 (02) ◽  
pp. 1750012 ◽  
Author(s):  
B. Pourhassan ◽  
J. Naji

In this paper, we consider tachyonic matter in spatially flat Friedmann–Robertson–Walker (FRW) universe, and obtain behavior of some important cosmological parameters for two special cases of potentials. First, we assume the exponential potential and then consider hyperbolic cosine type potential. In both cases, we obtain behavior of the Hubble, deceleration and EoS parameters. Comparison with observational data suggest the model with hyperbolic cosine type scalar field potentials has good model to describe universe.


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