Related papers: Spherical collapse with heat flow and without hori…
We use the Tolman metric to describe gravitational collapse of a sphere of a fluid without pressure in spacetime with the Hubble parameter $H$ related to the cosmological constant. We show that the largest radius of a galaxy formed from…
I use a simple analytical model to show that simple heat conduction models cannot significantly suppress cluster cooling flows. I build a static medium where heat conduction globally balances radiative cooling, and then perturb it. I show…
We study quantum radiation emitted during the collapse of a quantized, gravitating, spherical domain wall. The amount of radiation emitted during collapse now depends on the wavefunction of the collapsing wall and the background spacetime.…
We prove a non-collapsing property for curvature flows of embedded hypersurfaces in the sphere and in hyperbolic space.
A relativistic model of a heat conducting collapsing star, which includes thermal pre-relaxation processes, is presented. Particular attention is paid to the influence of a given parameter defined in terms of thermodynamic variables, on the…
A dynamical symmetry for spherical collapse has been studied using a linear transformation of the initial data set (mass and kinetic energy function) and the area radius. With proper choice of the initial area radius, the evolution as well…
We study the emission of space-time waves produced by back-reaction effects during a collapse of a spherically symmetric universe with a time dependent cosmological parameter, which is driven by a scalar field. As in a previous work the…
We address the question of radiation emitted from a collapsing star. We consider the simple model of a spherical star consisting of pressure-free dust and we derive the emission spectrum via a systematic asymptotic expansion of the complete…
The collapse of a vapor bubble near a flat solid boundary results in the formation of a jet that is directed towards the boundary. In more complex geometries such as corners, predictions of the collapse cannot be made in a straightforward…
We give a set of exact nonlinear closed--form solutions for the non-spherical collapse of pressure-less matter in Newtonian gravity, and indicate their possible cosmological applications. Keywords: Newtonian gravitation: free collapse,…
Gravitational collapse is analyzed in the Brane-World by arguing that regularity of five-dimensional geodesics require that stars on the brane have an atmosphere. For the simple case of a spherically symmetric cloud of non-dissipating dust,…
We find radiation in an infalling frame and present an explicit analytic evidence of the failure of no drama condition by showing that an infalling observer finds an infinite negative energy density at the event horizon. The negative and…
The sublimation/deposition process at a solid sphere of argon into its vapor in the presence of helium as a background gas is modeled applying the linearized Boltzmann equation, in which the McCormack model is employed for the collisional…
Concept of curvature of liquid surrounding a spherical surface seems obvious in daily life, but based on earthly conditions everywhere. However, our understanding about the concept seems more transparent when we keep the system out of the…
The self-similar decay of energy in a turbulent flow is studied in direct numerical simulations with and without rotation. Two initial conditions are considered: one non-helical (mirror-symmetric), and one with maximal helicity. The results…
We model the gravitational collapse of heavy massive shells including its main quantum corrections. Among these corrections, quantum improvements coming from Quantum Einstein Gravity are taken into account, which provides us with an…
We consider the problem of a rotating charged spherical shell of radius a carrying an axially symmetric distribution of charge. We give the interior and exterior solutions to this problem for arbitrary zonal dependence of the surface charge…
In the previous paper [Harada, Cardoso, and Miyata, Phys.\ Rev.\ D {\bf 99} (2019), 044039], it is shown that a hollow transmissive shell collapsing to an ultracompact object of radius very close to its horizon radius generally emits…
If we take into account the Hilbertian gravitational repulsion, even a dust sphere with a zero fluido-dynamical pressure collapses to a body of a comparatively small, finite, volume.
Thermal convection in fluid layers heated from below are usually realized experimentally as well as treated theoretically with fixed boundaries on which conditions for the temperature and the velocity field are prescribed. The thermal and…