Modelling of a spherical deflagration at constant speed

Diffusion at constant speed in a model phase space

We reconsider the problem of diffusion of particles at constant speed and present a generalization of the Telegrapher process to higher dimensional stochastic media (d > 1), where the particle can move along 2 d directions. We derive the equations for the probability density function using the " formulae of differentiation " of Shapiro and Loginov. The model is an advancement over similiar mode...

Modelling and Simulation of a 12 MW Active-Stall Constant-Speed Wind Farm

Spherical symmetric charged solution with cosmological constant

A spherically symmetric charged ideal fluid solution of Einstein field equation is given in the presence of the cosmological constant and two well known example of this type of solution is presented. If the matter is confined in a region, the exterior spacetime is considered as RN-de Sitter (Reissner-Nordström de Sitter) and to complete solution matching conditions are examined. We show that th...

Quasi-spherical collapse with cosmological constant

Gravitational collapse is one of the most important problem in classical general relativity. Usually, the formation of compact stellar objects such as white dwarf and neutron star are preceded by a period of collapse. Hence for astrophysical collapse, it is necessary to describe the appropriate geometry of interior and exterior regions and to determine proper junction conditions which allow the...

The Spherical Collapse Model in a Universe with Cosmological Constant

The spherical collapse model was first developed by Gunn & Gott 1 for a flat universe with no cosmological constant. It assumes that the process of formation of bound objects in the universe can be at first approximation described by evolution of an uniformly overdense spherical region in otherwise smooth background. Despite its simplicity, the model has been widely used to explain properties o...