Related papers: Scalar fields from nonlinear sigma models on black…
We investigate the effects of large scalar inhomogeneities during the kination epoch, a period in which the universe's dynamics are dominated by the kinetic energy of a scalar field, by fully evolving the Einstein equations using numerical…
We investigate, in the framework of a recently introduced new class of invariant geometrical scalar-tensor theory of gravity, the possibility that a viscous dark fluid can be described in a unified manner by a single scalar field. Thus we…
Spontaneous scalarization of black holes typically occurs through the condensation of a scalar field, with the field evolving from a $U(1)$-symmetric phase into a symmetry-breaking one with lower energy. We show that there exist…
Motivated by cosmic censorship in general relativity and string theory, we extend Christodoulou's celebrated examples of naked singularity formation in the Einstein-massless scalar field system to include a positive or negative scalar…
We studied the influence of dilaton field on the dynamical collapse of a charged scalar one. Different values of the initial amplitude of dilaton field as well as the altered values of the dilatonic coupling constant were considered. We…
We investigate the correction to the potential that gives rise to the bound orbits and radiation from non-spinning inspiralling binary black holes in a dark matter environment consisting of axion-like particles and dark photons using the…
Recent developments in the field of gravitational physics, including the emergence of gravitational wave astronomy, black hole images, and more accurate telescopes, have allowed us to probe the strong-field character of gravity in a novel…
We explore the question of how to probe the vacuum structure of space time by a massive scalar field through interaction with background gravitons. Using the $\Gamma$-regularization for the in-/out-state formalism, we find the effective…
Motivated by the goal for high accuracy modeling of gravitational radiation emitted by isolated systems, recently, there has been renewed interest in the numerical solution of the hyperboloidal initial value problem for Einstein's field…
In the spacetime of a $d$-dimensional static tense brane black hole we elaborate the mechanism by which massive scalar fields decay. The metric of a six-dimensional black hole pierced by a topological defect is especially interesting. It…
We study a new model of scalar field with a general non-minimal kinetic coupling to itself and to the curvature, as a source of dark energy, and analyze the cosmological dynamics of this model and the issue of accelerated expansion. A wide…
We study the cosmological evolution of an induced gravity model with a scale symmetry breaking potential for the scalar field. The radiation to matter transition, following inflation and reheating, influences the dynamics of such a field…
We examine the effects of a scalar field, coupled only to neutrinos, on oscillations among weak interaction current eigenstates. The existence of a real scalar field is manifested as effective masses for the neutrino mass eigenstates, the…
A Gauss-Bonnet (GB) coupled scalar field $\phi$, responsible for the late-time cosmic acceleration and interacting with a coherent scalar field $\psi$ through an interaction potential $W(\phi,\psi)$, is considered from the point of view of…
Although general relativity passes all precision tests to date, there are several reasons to go beyond the current model of gravitation and search for new fundamental physics. This means looking for new, so far undetected, fields. Scalars…
Using a scalar field as an intrinsic 'clock' while investigating the dynamics of gravitational systems has been successfully pursued in various researches on the border between classical and quantum gravity. The objective of our research…
The off-shell dynamics of the O(3) nonlinear sigma-model is probed in terms of spectral densities and two-point functions by means of the form factor approach. The exact form factors of the Spin field, Noether-current, EM-tensor and the…
This work presents a comparative analysis of the quasi-normal modes and ringdowns of scalar field perturbations in the non-commutative Schwarzschild black hole spacetime, focusing on two distinct non-minimal curvature couplings: in the…
Eigenfunctions for normal modes of scalar fields in BTZ black hole spacetime are studied. Orthonormal relations among them are derived. Quantization for scalar fields is done and particle number, energy and angular momentum are expressed by…
It was believed that when gravitational, electromagnetic and scalar waves interact, a spacelike curvature singularity or Cauchy horizon develops because of mutual focusing. We show with an exact solution that the collision of…