Related papers: Scalar Field Collapse with an exponential potentia…
The self-similar spherically symmetric perfect fluid space-time with scalar function incorporating linear equation of state is studied. The investigation of gravitational collapse conditions on the space-time determines that scalar function…
It is often the case that scalar fields are produced in the early Universe in the form of coherent oscillation. These scalar fields may have huge abundances and affect the evolution of the Universe. In particular, if the lifetime is long…
We describe results of a numerical calculation of circularly symmetric scalar field collapse in three spacetime dimensions with negative cosmological constant. The procedure uses a double null formulation of the Einstein-scalar equations.…
Galactic dark matter is modelled by a scalar field. In particular, it is shown that an analytically solvable toy model with a non-linear self-interaction potential U(Phi) leads to dark halo models which have the form of quasi-isothermal…
Scalar fields with inverse power-law effective potentials may provide a negative pressure component to the energy density of the universe today, as required by cosmological observations. In order to be cosmologically relevant today, the…
Examining the relativistic collapse of a spherical spacetime where gravity is coupled with a scalar field, this review provides a thorough analysis of some of the most relevant studies from both analytical and numerical perspectives. The…
Born-Infeld black holes in the Scalar-Tensor Theories of Gravity, in the case of massless scalar field, have been recently obtained. The aim of the current paper is to study the effect from the inclusion of a potential for the scalar field…
We present the numerical evolution of a massive test scalar fields around a Schwarzschild space-time. We proceed by using hyperboloidal slices that approach future null infinity, which is the boundary of scalar fields, and also demand the…
We present general exact solutions for two classes of exponential potentials in scalar field models for quintessence. The coupling is minimal and we consider only dust and scalar field. To some extent, it is possible to reproduce…
An attractive method of obtaining an effective cosmological constant at the present epoch is through the potential energy of a scalar field. Considering models with a perfect fluid and a scalar field, we classify all potentials for which…
We investigated the problem of the dynamical collapse of a self-gravitating complex charged scalar field in Einstein-Maxwell-dilaton theory with a phantom copuling for the adequate fields in the system under consideration. We also…
In this paper, we observe the collapse of a mass-less scalar field covariantly. We show that the strengths of the collapsing and dispersing modes of this scalar field will decide whether the collapse will end up in a black-hole or disperse.…
We study the proposal to solve the coincidence problem in the non-local version of the vacuum energy sequestering mechanism by means of a scalar field in a linear potential. We show that there is no solution in the theory compatible with…
We investigate the possibility to localize scalar field configurations as a model for black hole accretion. We analyze and resolve difficulties encountered when localizing scalar fields in General Relativity. We illustrate this ability with…
We report a new critical solution found at the threshold of axisymmetric gravitational collapse of a complex scalar field with angular momentum. To carry angular momentum the scalar field cannot be axisymmetric; however, its azimuthal…
As a candidate for dark matter in galaxies, we study an SU(3) triplet of complex scalar fields which are non-minimally coupled to gravity. In the spherically symmetric static spacetime where the flat rotational velocity curves of stars in…
Exact cosmological models for a scalar field in Lyra geometry are studied in the presence of a time-varying effective cosmological term originated from the specific interaction of an auxiliary $\Lambda$ - term with the displacement vector.…
The cosmological consequences of a slow rolling scalar field with constant kinetic term in analogy to the vertical movement of a skydiver after reaching terminal velocity are investigated. It is shown that the terminal scalar field…
Covariant, self-interacting scalar quantum field theories admit solutions for low enough spacetime dimensions, but when additional divergences appear in higher dimensions, the traditional approach leads to results, such as triviality, that…
We present a model of vacuum tunneling through a classically forbidden region where a scalar field changes its value simultaneously over the entire volume of a (meta)stable ancestor vacuum with spherical curvature. The tunneling leaves the…