Related papers: Dark matter and generation of galactic magnetic fi…
In this letter, we discuss generation of magnetic field from cosmological perturbations. We consider the evolution of three component plasma (electron, proton and photon) evaluating the collision term between elecrons and photons up to the…
It seems necessary to suppress, at least partially, the formation of structure on subgalactic scales. As an alternative to warm or collisional dark matter, I postulate a condensate of massive bosons interacting via a repulsive interparticle…
The basic idea in this Letter is the assumption that masses of the galactic constituents (particles of short-living fluctuations) may be functions of strength of the gravitational field. They may be in galactic space heavier than in the…
The processes are investigated by which gas loses its angular momentum during the protogalactic collapse phase, leading to disk galaxies that are too compact with respect to the observations. High-resolution N-body/SPH simulations in a…
In this work the phenomenology of models possessing a non-minimal coupling between matter and geometry is discussed, with a particular focus on the possibility of describing the flattening of the galactic rotation curves as a dynamically…
Detection of a surprisingly high flux of positron annihilation radiation from the inner galaxy has motivated the proposal that dark matter is made of weakly interacting light particles (possibly as light as the electron). This scenario is…
In this Letter we point out to the possibility that the cloud of the vacuum energy excitations in gravitation fields surrounding galaxies forms a component of dark matter. These clouds of the vacuum energy excitations interact…
The hypothesis that dark matter consists of superheavy particles with the mass close to the Grand Unification scale is investigated. These particles were created from vacuum by the gravitation of the expanding Universe and their decay led…
It is shown that in the spacetime dominated by a cosmological constant, in the far region of a Schwarzschild-de Sitter black hole, a seed magnetic field can be generated in an ambient plasma (in a state of no magnetic field) by a…
Observations of density profiles of galaxies and clusters constrain the properties of dark matter. Formation of stable halos by collisional fluids with very low mass particles appears as the most probable interpretation, while halos formed…
The pervasive presence in space of a flux of high-speed, electrically uncharged dark matter particles is examined here for potential consequences. Dark matter interactions with ordinary matter are considered, and a model of the dark matter…
There are at present more then 30 theories about the origin of cosmic magnetic fields at galactic and intergalactic scales. Most of them rely on concepts of elementary particle physics, like phase transitions in the early Universe, string…
We review progress in understanding the formation of galactic disks in the standard cosmogonic scenario involving gravitational clustering of baryons and dark matter and dissipative collapse of the baryons. This scenario accounts remarkably…
The proposition that dark matter halos possess angular momentum, though widely accepted, is a theoretical prediction which has, till date, not been observationally verified. The gravi-magnetic field produced by a rotating gravitating object…
One of the major challenges of modern physics is to decipher the nature of dark matter. Astrophysical observations provide ample evidence for the existence of an invisible and dominant mass component in the observable universe, from the…
Dark matter in the universe seems to be one of the most important puzzles science has to face in this moment. In this essay we point out that dark matter could be a spin-0 fundamental interaction of Nature rather than a simple particle.…
We show that strong magnetic fields can be generated at shock waves associated with formation of galaxies or clusters of galaxies by the Weibel instability, an instability in collisionless plasmas. The estimated strength of the magnetic…
Magnetic fields in our Galaxy and nearby galaxies have been revealed by starlight polarization, polarized emission from dust grains and clouds at millimeter and submillimeter wavelength, the Zeeman effect of spectral lines or maser lines…
The nonbaryonic dark matter of the Universe is assumed to consist of new stable particles. A specific case is possible, when new stable particles bear ordinary electric charge and bind in heavy "atoms" by ordinary Coulomb interaction. Such…
The particles of a dark matter due to gravitational interaction deviate from straight trajectories in the vicinity of a massive body. This causes their density to become inhomogeneous. The developed density contrast causes a gravitation…