Related papers: Can Dark Matter be a Scalar Field?
We argued that the standard field scalar potential couldn't be widely used for getting the adequate galaxies' curve lines and determining the profiles of dark matter their halo. For discovering the global properties of scalar fields that…
In a previous article due to one of the present authors (YFP), an extension to General Relativity, violating general covariance to the residual unimodular one, was proposed. As a manifestation of such a violation, there appears the…
Using recent precision measurements of cosmological paramters, we re-examine whether these observations alone, independent of type Ia supernova surveys, are sufficient to imply the existence of dark energy. We find that best measurements of…
We study the interaction between dark matter and dark energy, with dark energy described by a scalar field having a double exponential effective potential. We discover conditions under which such a scalar field driven solution is a late…
Astronomical observations from small galaxies to the largest scales in the universe can be consistently explained by the simple idea of dark matter. The nature of dark matter is however still unknown. Empirically it cannot be any of the…
The cosmic evolution of a dark matter model which behaves relativistically in the early Universe is explored. Dark matter is described as a complex scalar field, whose earliest evolution is characterized by a stiff equation of state ($p…
We discuss the cosmological consequences of an interacting model in the dark sector in which the $\Lambda$ component evolves as a truncated power series of the Hubble parameter. In order to constrain the free parameters of the model we…
Cosmological and astrophysical measurements indicate that the universe contains a large amount of dark matter. A number of weak scale dark matter candidates have been proposed in extensions of the standard model. The potential to discover…
Several attempts to solve the cosmological constant problem, which concerns the value of the cosmological constant being extremely smaller than the Standard Model mass scales, have introduced a scalar field with a very flat potential that…
Dark matter is one of the pillars of the current standard model of structure formation: it is assumed to constitute most of the matter in the Universe. However, it can so far only be probed indirectly through its gravitational effects, and…
We consider a simple extension of the Standard Model by the addition of N real scalar gauge singlets $\vp$ that are candidates for Dark Matter. By collecting theoretical and experimental constraints we determine the space of allowed…
We consider a model where a light scalar field (with mass $\lesssim 30\, {\rm eV}$), conjectured to be dark matter, has a non-minimal coupling to gravity. In the non-relativistic limit, this new coupling introduces a self-interaction term…
Aims. We investigated the gravitational effects of a scalar field within scalar-tensor gravity as an alternative to dark matter. Motivated by chameleon, symmetron and f(R)-gravity models, we studied a phenomenological scenario where the…
We examine the possibility that galactic halos are collisionless ensembles of scalar field ``massive compact halo objects'' (MACHOs). Using mass constraints from MACHO microlensing and from theoretical arguments on halos made up of massive…
Scalar field dark matter offers an interesting alternative to the traditional WIMP dark matter picture. Astrophysical and cosmological simulations are useful to constraining the mass of the dark matter particle in this model. This is…
The last decade has seen unprecedented effort in dark matter model building at all mass scales coupled with the design of numerous new detection strategies. Transformative advances in quantum technologies have led to a plethora of new…
It has recently been argued that string theory does not admit de Sitter vacua. This would imply that the current accelerated expansion of the universe is not driven by a cosmological constant (or vacuum energy) but by other means such as a…
Owing to the renewed interest in dark matter after the upgrade of the large hadron collider and its dedication to dark matter research it is timely to reassess the whole problem. Considering dark matter is one way to reconcile the…
Nowadays cosmological inflation is the most accepted mechanism to explain the primordial seeds that led to the structure formation observed in the Universe. Current observations are in well agreement to initial adiabatic conditions, which…
In this study, we have explored a scalar field cosmological model in the axially symmetric Bianchi type-I universe. In this study, our aim is to constrain the scalar field dark energy model in an anisotropic background. For this purpose,…