We study the critical collapse of a massive complex scalar field coupled minimally to gravity. Taking as initial data simple Gaussian pulse with shape similar harmonic ansatz for boson stars, we obtain type I and II when varying width $\ensuremath{\sigma}$. For $\ensuremath{\sigma}\ensuremath{\le}0.5$ find exponent $\ensuremath{\gamma}=0.38\ifmmode\pm\else\textpm\fi{}0.01$ an echoing period $\m...

The DeWitt-Schwinger proper time point-splitting procedure is applied to a massive complex scalar field with arbitrary curvature coupling interacting with a classical electromagnetic field in a general curved spacetime. The scalar field current is found to have a linear divergence. The presence of the external background gauge field is found to modify the stress-energy tensor results of Christe...

The DeWitt-Schwinger proper time point-splitting procedure is applied to a massive complex scalar field with arbitrary curvature coupling interacting with a classical electromagnetic field in a general curved spacetime. The scalar field current is found to have a linear divergence. The presence of the external background gauge field is found to modify the stress-energy tensor results of Christe...

Critical gravitational collapse was first found by Choptuik[1] in simulations of a spherically symmetric massless scalar field. A natural question to pose is then how critical collapse behaves when the scalar field has a mass, since this will introduce a characteristic length that destroys the scale invariance of the field equations. This question was studied by Brady et. al.[2] The results of ...

In this paper we construct the Nonsymmetric Jordan–Thiry Theory unifying N.G.T., the Yang–Mills’ field, the Higgs’ fields and scalar forces in a geometric manner. In this way we get masses from higher dimensions. We discuss spontaneous symmetry breaking, the Higgs’ mechanism and a mass generation in the theory. The scalar field Ψ (as in the classical Jordan–Thiry Theory) is connected to the eff...

Born-Infeld black holes in the Scalar-Tensor Theories of Gravity, in the case of massless scalar field, have been recently obtained [1, 2, 3]. The aim of the current paper is to study the effect from the inclusion of a potential for the scalar field in the theory, through a combination of analytical techniques and numerical methods. The black holes coupled to a massive scalar field have richer ...

 Casimir entropy is an important aspect of casimir effect and at the nanoscale is visible. In this paper, we employ the path integral method to ‎obtain a‎ ‎general‎ relation for casimir entropy and ‎i‎nternal energy of arbitrary shaped objects in the presence of two, three and four dimension scalar fields and ‎the‎ electromagnetic field. For this purpose, using Lagrangian and based on a perturb...

Born-Infeld black holes in the Scalar-Tensor Theories of Gravity, in the case of massless scalar field, have been recently obtained [1, 2, 3]. The aim of the current paper is to study the effect from the inclusion of a potential for the scalar field in the theory, through a combination of analytical techniques and numerical methods. The black holes coupled to a massive scalar field have richer ...

We look for the necessary conditions allowing the Universe isotropisation in presence of a minimally coupled and massive scalar field with a perfect fluid. We conclude that it arises only when the Universe is scalar field dominated, leading to flat spacelike sections and accelerated expansion, and examine the case of a SUGRA theory. Published in Class. Quantum Grav. vol 21, 6, 1609-1621, 2004