Related papers: Dynamics of Tachyonic Dark Matter
Cosmological arguments proving that the universe is dominated by invisible non-baryonic matter are reviewed. Possible physical candidates for dark matter particles are discussed. A particular attention is paid to non-compensated remnants of…
The standard model of particle physics is marvelously successful. However, it is obviously not a complete or final theory. I shall argue here that the structure of the standard model gives some quite concrete, compelling hints regarding…
The evidence for the existence of dark matter in the universe is reviewed. A general picture emerges, where both baryonic and non-baryonic dark matter is needed to explain current observations. In particular, a wealth of observational…
As an explanation for the acceleration of the universe, we propose dark matter with self-interactions characterized by a negative pressure; there is no vacuum energy whatsoever in this Cardassian model. These self-interactions may arise due…
It is proposed that an ultra-light fermionic species, dubbed cosmic magnino has condensed into a ferromagnetic state in the Universe. The extended structure of domain walls associated with this ferromagnetism accounts for the observed Dark…
It is shown that a present acceleration with a past deceleration is a possible solution of the Friedmann equation by considering the Universe as a mixture of a scalar with a matter field and by including a non-equilibrium pressure term in…
The acceleration of the cosmic expansion is a fundamental challenge to standard models of particle physics and cosmology. The new physics of dark energy may lie in the nature of gravity, the quantum vacuum, or extra dimensions. I give a…
In the standard model of cosmology, the present evolution of the Universe is determined by the presence of two components of unknown nature. One of them is referenced as ``dark matter'' to justify the fact that it behaves cosmologically…
Observing the Universe, astronomers have concluded that the motion of stars can not be accounted for unless one assumes that most of the mass in the Universe is carried on by a ``dark matter", so far impervious to all attempts at being…
In the present work we study a dark energy model in which a non-linear scalar field (tachyon) with a Born-Infeld type of action is responsible for the observed cosmic acceleration. The potential of the tachyon is well-motivated since it…
It is argued that the discovery of cosmic acceleration could have been anticipated on thermodynamic grounds, namely, the generalized second law and the approach to equilibrium at large scale factor. Therefore, the existence of dark energy…
The dynamical analysis for coupled dark energy with dark matter is presented, where a complex scalar field is taken into account and it is considered in the presence of a barothropic fluid. We consider three dark energy candidates:…
Growing amount of data show evidence for statistical and apparent physical association between low-redshift galaxies and high-redshift quasi-stellar objects, suggesting noncosmological origin of their redshift and failure of classical…
QCD axions are a well-motivated candidate for cold dark matter. Cold axions are produced in the early universe by vacuum realignment, axion string decay and axion domain wall decay. We show that cold axions thermalize via their…
Axions are well-motivated dark matter candidates with simple cosmological production mechanisms. They were originally introduced to solve the strong CP problem, but also arise in a wide range of extensions to the Standard Model. This…
Main aim of this work is to give a suitable explanation of present accelerating universe through an acceptable interactive dynamical cosmological model. A three-fluid cosmological model is introduced in the background of…
As it follows from the classical analysis of the data, the paper is intended to solve one of the main problems in the physics of tachyons, they are having imaginary mass. Further we use quantum mechanics to deal with the matters concerning…
The search for supersymmetric partners at Large Hadron Collider revealed negative result. Though, strictly speaking, it does not exclude low energy supersymmetry, but still it leads to strong constraints of the parameter space. Therefore…
We investigate the cosmological dynamics of the recently proposed extended chameleon models at both background and linear perturbation levels. Dynamical systems techniques are employed to fully characterize the evolution of the universe at…
The possible conversion of neutron matter to strange matter and its relevance to astrophysical problems are discussed. Particular attention is paid to the {\it form} in which this hypothetical burning process should be propagated in dense…