We study the spherically symmetric collapse of a real, minimally coupled, massive scalar field in an asymptotically Einstein–de Sitter spacetime background. By means of an eikonal approximation for the field and metric functions, we obtain a simple analytical criterion—involving the physical size and mass scales ~the field’s inverse Compton wavelength and the spacetime gravitational mass! of th...

Neutrinos emitted during stellar core collapse up to their trapping phase carry information about the stage from which the Supernova explosion process initiates. The dominant e emission mechanism is by electron capture on free protons and f-p shell nuclei and the spectrum of these neutrinos is a function of the ambient physical conditions within the core as well as the nuclear equation of state...

Turbulence governed by a generalized nonlinear Schrödinger equation (GNSE) including viscous heating and nonlinear damping is numerically investigated. It is found that a large localized pulse can suffer modulational instability and then collapse into the shortest-wavelength modes, as for the classical nonlinear Schrödinger equation. However, the total energy of the nonconservative GNSE can als...

In the present paper we consider, using our earlier results, the process of quantum gravitational collapse and argue that there exists the final quantum state when the collapse stops. This state, which can be called the “no-memory state”, reminds the final “no-hair state” of the classical gravitational collapse. Translating the “no-memory state” into classical language we construct the classica...

Cold collapse of a cluster consisting of small identical clumps, each of which is in equilibrium, is considered. At the beginning the clumps have no relative motion, and then the cluster collapses by its gravity. At the first collapse most of the clumps are destroyed, but some clumps survive. From numerical simulations, we obtained a empirical condition of the number and the size of the clumps ...

The complete spectrum of the endstates naked singularities, or blackholes of gravitational collapse is analyzed for a wide class of N -dimensional spacetimes in spherical symmetry, which includes and generalizes the dust solutions and the case of vanishing radial stresses. The final fate of the collapse is shown to be fully determined by the local behavior of a single scalar function and by the...

We have measured the heat capacity of (3)He-(4)He mixtures confined in films of thickness 48.3 and 986.9 nm. The confinement is defined by direct bonding of two silicon wafers. The heat capacity is measured using an ac technique and then transformed to correct for exponent renormalization effects. The data address the expected universal critical behavior along the lambda line as function of (3)...