NUMERICAL INVESTIGATION OF FIVE-DIMENSIONAL GRAVITATIONAL COLLAPSES

Formation of Five-Dimensional String Solutions from the Gravitational Collapse

We study the formation of five-dimensional string solutions including the Gregory-Laflamme (GL) black string, the Kaluza-Klein (KK) bubble, and the geometry with a naked singularity from the gravitational collapse. The interior solutions of five-dimensional Einstein equations describe collapsing non-isotropic matter clouds. It is shown that the matter cloud always forms the GL black string solu...

Critical Phenomena in Gravitational Collapses of Neutron Star Systems

We study critical phenomena in gravitational collapses of stellar objects based on numerical solutions of the Einstein equations. We discovered that stellar objects with large kinetic energy described by an equation of state (EOS) commonly used in describing neutron star matter may undergo critical collapses. To the best of our knowledge, this is the first study showing that critical collapses ...

Einstein-Maxwell gravitational instantons and five dimensional solitonic strings

We study various aspects of four dimensional Einstein-Maxwell multicentred gravitational instantons. These are half-BPS Riemannian backgrounds of minimal N = 2 supergravity, asymptotic to R4, R3 ×S1 or AdS2 ×S2. Unlike for the Gibbons-Hawking solutions, the topology is not restricted by boundary conditions. We discuss the classical metric on the instanton moduli space. One class of these soluti...

Collapses of two-dimensional granular columns.

The first detailed quantitative observations of the two-dimensional collapse of a granular column along a horizontal channel are presented for a variety of materials. Together with the complementary study for the axisymmetric situation, we conclude that for granular collapses the generally accepted approaches, that are highly dependent on frictional parameters, do not describe the main flow phe...

Numerical Investigation of the Structure of Density Currents in a two Dimensional Channel