Related papers: Can particle creation phenomena replace dark energ…
It is suggested that the apparently disparate cosmological phenomena attributed to so-called 'dark matter' and 'dark energy' arise from the same fundamental physical process: the emergence, from the quantum level, of spacetime itself. This…
Analyses of internal galaxy and cluster dynamics typically employ Newton's law of gravity, which neglects the field self-interaction effects of General Relativity. This may be why dark matter seems necessary. The Universe evolution, on the…
Particle production processes in the expanding universe are described within a simple kinetic model. The equilibrium conditions for a Maxwell-Boltzmann gas with variable particle number are investigated. We find that radiation and…
A set of cosmological models that takes into account the variation of the particle number is presented. In this context both dark matter and dark energy can be explained using a single component, without assuming any exotic equation of…
Starting with the de Broglie--Proca Lagrangian for a massive vector field, we calculate the number density of particles resulting from gravitational particle production (GPP) during inflation, with detailed consideration to the evolution of…
We review progress in understanding dark matter by astrophysics, and particularly via the effect of gravitational lensing. Evidence from many different directions now all imply that five sixths of the material content of the universe is in…
The theoretical and observational consequences of thermodynamics of open systems, which allow particle creation are investigated in modified $f(R,T)$ ($R$ is the Ricci scalar and $T$ is the trace of energy-momentum tensor) theory of gravity…
We consider a gravitational analogue of the Schwinger effect in a cosmological context. While the Schwinger effect is usually attributed to a static electric background, its derivation is actually based on a switching on/off of the electric…
We investigate the creation of dark matter particles as a result of the decay of the scalar field in the framework of warm inflationary models, by using the irreversible thermodynamics of open systems with matter creation/annihilation. We…
The non-Keplerian galactic rotational curves and the gravitational lensing data strongly indicate a significant dark matter component in the universe. Moreover, these data can be combined to deduce the equation of state of dark matter. Yet,…
We propose a comprehensive theory of dark matter that explains the recent proliferation of unexpected observations in high-energy astrophysics. Cosmic ray spectra from ATIC and PAMELA require a WIMP with mass M_chi ~ 500 - 800 GeV that…
Modified gravity theories with a nonminimal coupling between curvature and matter offer a compelling alternative to dark energy and dark matter by introducing an explicit interaction between matter and curvature invariants. Two of the main…
Traditional quantum theory can be used to construct hypothetical very large-scale gravitational stationary state structures from traditionally stable atoms and subatomic particles. These so called "gravitational macro-eigenstructures" have…
Using an approximate solution to the $N$-body problem in general relativity, and the \emph{principle of local isotropy at any point}, we construct a cosmological model, with zero curvature, for a universe composed uniquely by collision-less…
In recent years, unprecedented progress in observational cosmology has revealed a great deal of information about the formation and evolution of structures in the universe. This, in turn, has raised many challenging issues for the…
It is now, generally, believed that the presence of some form of dark matter is essential to explain the flat rotation curves of galaxies, and anomalous large velocities of galaxies in the clusters and superclusters. This dark matter turns…
Recent observations suggest that the number of relativistic degrees of freedom in the early universe might exceed what is predicted in the standard cosmological model. If even a small, percent-level fraction of dark matter particles are…
The possibility that around some astrophysical objects there are non-static magnetic fields of enormous intensity suggests that in these situations real particles may be produced. The slowness of the variation is compensated by the huge…
Super-high energy corpuscular and gamma rays as well as cosmic high--power density sources are hard to explain in a galaxy model framework. Attempts to include some of those phenomena in the Standard Cosmological Model also encounter…
Dark photons are a theorized massive spin-1 particle which can be produced via various mechanisms, including cosmological gravitational particle production (GPP) in the early universe. In this work, we extend previous results for GPP of…