Interacting Dark Energy and the Cosmic Coincidence Problem

The introduction of an interaction for dark energy to the standard cosmology offers a potential solution to the cosmic coincidence problem. We examine the conditions on the dark energy density that must be satisfied for this scenario to be realized. Under some general conditions we find a stable attractor for the evolution of the Universe in the future. Holographic conjectures for the dark energy offer some specific examples of models with the desired properties.Comment: 8 pages, 3 figures, Phys. Rev. D versio

The effect of tensor interaction in splitting the energy levels of relativistic systems

In this paper we solve analytically Dirac equation for Eckart plus Hulthen potentials with Coulomb-like and Yukawa-like tensor interaction in the presence of Spin and Pseudo-spin Symmetry for any k number. The Parametric Nikiforov-Uvarov method is used to obtain the energy Eigen-values and wave functions. We also discuss the energy Eigen-values and the Dirac spinors for the Eckart plus Hulthen potentials for the spin and pseudo-spin symmetry with PNU method. To show the accuracy of the present model, some numerical results are shown in both pseudo-spin and spin symmetry limits.Comment: 19 Pages, 13 Figures,6 Tabl

Intuitionistic Hesitant Fuzzy Filters in BE-Algebras

The notions of hesitant fuzzy filters and hesitant implicative filter was introduced. In this paper, we introduce the notion of intuitionistic hesitant fuzzy filters (IHFF) and intuitionistic hesitant implicative filters (IHIFB) and several properties are investigated. Also, we defined ?-level sets, and we show the relation between IHFF, IHIFF and ?-Level