Related papers: Gravitational Excitons as Dark Matter
Theories of dynamical electroweak symmetry breaking predict a strong first order cosmological phase transition: we compute the resulting signals, primordial black holes and gravitational waves. These theories employ one SM-neutral scalar,…
We propose to search for scalar dark matter via its effects on the electromagnetic fine-structure constant and particle masses. Scalar dark matter that forms an oscillating classical field produces `slow' linear-in-time drifts and…
We explore the scalar field obtained under the conformal transformation of the spacetime metric $g_{\mu\nu}$ from the Jordan frame to the Einstein frame in $f(R)$ gravity. This scalar field is the result of the modification in the…
Gravitational force manifested in its affect on rotational velocity is what indicates the presence of dark matter in individual galaxies. Newtonian mechanics is generally used to derive the relationship between rotational velocity and…
In the timescape scenario cosmic acceleration is understand as an apparent effect, due to gravitational energy gradients that grow when spatial curvature gradients become significant with the nonlinear growth of cosmic structure. This…
As has been shown before (a brief comment will be given in the text), relativistic mass and relativistic time dilation of moving bodies are equivalent as well as time and mass in the rest frame. This implies that the time dilation due to…
We propose a new class of quintessence models in which late times oscillations of a scalar field give rise to an effective equation of state which can be negative and hence drive the observed acceleration of the universe. Our ansatz…
Dark matter, one of the fundamental components of the universe, has remained mysterious in modern cosmology and particle physics, and hence, this field is of utmost importance at present moment. One of the foundational questions in this…
[abridged] Recently, in Benetti et al. (Astrophys. J. 2023, 949, 65), we suggested that the dark matter (DM) component in galaxies may originate fractional gravity. In such a framework, the DM component exists, but the gravitational…
Starting with geometrical premises, we infer the existence of fundamental cosmological scalar fields. We then consider physically relevant situations in which spacetime metric is induced by one or, in general, by two scalar fields, in…
It is shown that the curvature of space-time induced by vacuum fluctuations of quantum fields should be proportional to the square of Newton's constant $G$. This offers a possible explanation for the success of the approximation $G m^6 c^2…
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…
Scale-invariant fluctuations and cold dark matter could originate from two different modes of a single scalar field, fluctuations from massless Goldstone oscillations and matter from massive Higgs modes. Matching the fluctuations and dark…
Scalar fields coupled to gravity via $\xi R {\Phi}^2$ in arbitrary Friedmann-Robertson-Walker backgrounds can be represented by an effective flat space field theory. We derive an expression for the scalar energy density where the effective…
An effective energy tensor for gravitational radiation is identified for uniformly expanding flows of the Hawking mass-energy. It appears in an energy conservation law expressing the change in mass due to the energy densities of matter and…
We present numerical $N$-body simulation studies of large-scale structure formation. The main purpose of these studies is to analyze the several models of dark matter and the role they played in the process of large-scale structure…
The nature of dark matter remains one of the greatest unsolved mysteries in elementary particle physics. It might well be that the dark matter particle belongs to a dark sector completely secluded or extremely weakly coupled to the visible…
We have shown that inflatons with a mass which is calculated to be of the order of $10^{10}\GeV$ can constitute a dominant part of dark matter. They can decay uniquely into a neutrino and antineutrino with a lifetime calculated to be…
The standard model Higgs boson can serve as the inflaton field of slow roll inflationary models provided it exhibits a large non-minimal coupling with the gravitational scalar curvature. The Higgs boson self interactions and its couplings…
The cosmological history and evolution are examined for gravitational models with interaction in the dark sector of the universe. In particular, we consider the dark energy to be described by a phantom scalar field and the dark matter $\rho…