Related papers: On the dynamics of relativistic multi-layer spheri…
We study the evolution of the universe which contains a multiple number of non-relativistic scalar fields decaying into both radiation and pressureless matter. We present a powerful analytic formalism to calculate the matter and radiation…
We make a detailed analysis of Newtonian as well as relativistic core-shell models recently proposed to describe a black hole or neutron star surrounded by shells of matter, and in a seminal sense also galaxies, supernovae and star remnants…
We consider thin spherical shells of matter in both Newtonian gravity and general relativity, and examine their equilibrium configurations and dynamical stability. Thin-shell models are admittedly a poor substitute for realistic stellar…
The long time dynamics of large particles trapped in two inhomogeneous turbulent shear flows is studied experimentally. Both flows present a common feature, a shear region that separates two colliding circulations, but with different…
The dynamics and stability of a thin gas layer moving between two fluid layers moving in the same or opposite direction is studied. The linear evolutionary equations describing the spatial-temporal dynamics of the interface perturbations…
We use SPH simulations to investigate the gravitational fragmentation of expanding shells through the linear and non--linear regimes. The results are analysed using spherical harmonic decomposition to capture the initiation of structure…
We investigate the hydrodynamical evolution of an ultra-relativistic fireball colliding with a freely expanding gas. The hydrodynamical interaction of the fireball and the gas results in the formation of a geometrically thin shell. We study…
We investigate spherically symmetric gravitational collapse of thick matter shell without radiation in the Einstein gravity with cosmological constant. The orbit of the infalling thick matter is determined by imposing an equation of state…
Numerical simulations of galaxy clusters including two species -- baryonic gas and dark matter particles --are presented. Cold Dark Matter spectrum, Gaussian statistics and flat universe are assumed. The dark matter component is evolved…
The study of the dynamical evolution of massive black hole pairs in mergers is crucial in the context of a hierarchical galaxy formation scenario. The timescales for the formation and the coalescence of black hole binaries are still poorly…
We perform a numerical free evolution of a selfgravitating, spherically symmetric scalar field satisfying the wave equation. The evolution equations can be written in a very simple form and are symmetric hyperbolic in Eddington-Finkelstein…
The time evolution of a particle, caught in an infinitely deep square well, displays unexpected features, when one includes tiny relativistic effects. Indeed, even the smallest corrections to the non-relativistic quadratic spectrum manifest…
The correlation buildup and the formation dynamics of the shell structure in a spherically confined one-component plasma are studied. Using Langevin dynamics simulations the relaxation processes and characteristic time scales and their…
The evolution of substructure embedded in non-dissipative dark halos is studied through N-body simulations of isolated systems, both in and out of initial equilibrium, complementing cosmological simulations of the growth of structure. We…
We explore the morphological and dynamical evolution of galaxy clusters in simulations using scalar and vector-valued Minkowski valuations and the concept of fundamental plane relations. In this context, three questions are of fundamental…
We provide a new multi-waveband compilation of the data describing the cosmological evolution of quasars, and discuss a model that attributes the evolution to variation in the rate of merging between dark halos in a hierarchical universe.…
We explore the dynamical evolution of spherically symmetric objects made of electrically counterpoised dust in general relativity. It has been claimed that these objects are in neutral equilibrium and, therefore, that black hole mimickers…
We study the time evolution of the entropy of a collapsing charged spherical domain wall, from the point of view of an asymptotic observer, by investigating the entropy of the entire system (i.e. charged domain wall and radiation) and…
We study the stochastic evolution of four species in cyclic competition in a well mixed environment. In systems composed of a finite number $N$ of particles these simple interaction rules result in a rich variety of extinction scenarios,…
We describe the possible scenarios for the evolution of a thin spherically symmetric self-gravitating phantom shell around the Schwarzschild black hole. The general equations describing the motion of the shell with a general form of…