相关论文: Tachyonic dark matter
As cosmology has entered a phase of precision experiments, the content of the universe has been established to contain interesting and not yet fully understood components, namely dark energy and dark matter. While the cause and exact nature…
The quanta of phantom dark energy models are negative energy particles, whose maximum magnitude of energy $|E|$ must be less than a cutoff $\Lambda\lesssim 20\,$MeV. They are produced by spontaneous decay of the vacuum into phantoms plus…
Recently tachyonic field has been depicted as dark energy model to represent the present acceleration of the Universe. In this paper we have considered mixture of tachyonic fluid with a perfect fluid. For this purpose we have considered…
The fact that the energy densities of dark energy and matter are similar currently, known as the coincidence problem, is one of the main unsolved problems of cosmology. We present here a model in which a spatial curvature of the universe…
The standard model of cosmology relies on the existence of two components, "dark matter" and "dark energy", which dominate the expansion of the Universe. There is no direct proof of their existence, and their nature is still unknown. Many…
The thorny issue of relating information theory to cosmology is here addressed by assuming a possible connection between quantum entanglement measures and observable universe. In particular, we propose a cosmological toy model, where the…
The consideration of dark energy's quanta, required also by thermodynamics, introduces its chemical potential into the cosmological equations. Isolating its main contribution, we obtain solutions with dark energy decaying to matter or…
We study the vacuum condensate characterizing many physical phenomena. We show that such a condensate may leads to non-trivial components of the dark energy and of the dark matter and may induces the spontaneous supersymmetry breaking, in a…
I briefly review our current understanding of dark matter and dark energy. The first part of this paper focusses on issues pertaining to dark matter including observational evidence for its existence, current constraints and the `abundance…
It is now believed that the universe is composed of a small amount of the normal luminous matter, a substantial amount of matter (Cold Dark Matter: CDM) which is non-luminous and a large amount of smooth energy (Dark Energy: DE). Both CDM…
Observations seem to indicate that our universe is presently accelerating due to the presence of dark energy. Quintessence represents a possible way to model the dark energy. In these proceedings, we briefly review its main properties.
We study a dark energy scenario in the presence of a tachyon field $\phi$ with potential $V(\phi)$ and a barotropic perfect fluid. The cosmological dynamics crucially depends on the asymptotic behavior of the quantity…
A new model for the universe filled with a generalized Chaplygin fluid is considered which unitarily describes as a single vacuum entity both a quintessence scalar field and a cosmological constant, so unifying the notion of dark energy.…
This paper deals with dark and phantom energy in the tachyon and sub-quantum models for dark energy. We obtain that the simplest condition for such a regime to occur in these scenarios is that the scalar field be Wick rotated to imaginary…
In this paper we consider tachyonic matter in spatially at FRW universe, and obtain behavior of some important cosmological parameters for two special cases of potentials. First we assume the exponential potential and then consider…
Cosmologists are just beginning to probe the properties of the cosmic vacuum and its role in reversing the attractive pull of gravity to cause an acceleration in the expansion of the cosmos. The cause of this acceleration is given the…
Currently available Type Ia distant supernovae observed data seem to support evidence that the cosmic expansion of the universe is accelerating. This unexpected result is beyond any standard model of modern cosmology. The new concept…
A minus sign is inserted, for good reason, into the formula for the Energy-Momentum Tensor for tachyons. This leads to remarkable theoretical consequences and a plausible explanation for the phenomenon called Dark Energy in the cosmos.
The introduction of an interaction for dark energy to the standard cosmology offers a potential solution to the cosmic coincidence problem. We examine the conditions on the dark energy density that must be satisfied for this scenario to be…
This work is focused on the exploration of the thermodynamics foundations of the matter creation scenario when a generalized form of the second law of thermodynamics for this scheme is implemented. In this scenario we consider an expanding…