THE SPHERICAL SYMMETRY BLACK HOLE COLLAPSE IN EXPANDING UNIVERSE

The spherical symmetry black holes are considered in expanding background. The singularity line and the marginally trapped tube surface behavior are discussed. In particular, we address the conditions whether dynamical horizon forms for these cosmological black holes. We also discuss about the cosmological constant effect on these black hole and the redshift of the light which comes from the marginally trapped tube surface.

BRIGHT AND DARK SOLITARY WAVES IN KERR MEDIUM WITH HIGHER ORDER LINEAR AND NONLINEAR DISPERSIONS

The existence of both bright and dark solitary wave solutions has been demonstrated for higher order nonlinear Schrödinger (HNLS) equation containing up to the fourth order linear and the second order nonlinear dispersion. We found that the solutions are completely characterized by the material properties and free from arbitrary parameters in contrast to solutions of the pure NLS equation. The two types of solution were further shown to have complementary parameter space and share a singularity line of asymptotic values ±∞ for the solitary envelope velocities.