Related papers: Quintessential Phenomena in Higher Dimensional Spa…
In this paper, we consider three different models of dark energy in higher dimensional space-time and discuss about some cosmological parameters numerically. The first model is a single component universe including viscous varying modified…
We propose a new approach to the Cosmological Constant Problem which makes essential use of an extra dimension. A model is presented in which the Standard Model vacuum energy ``warps'' the higher-dimensional spacetime while preserving 4D…
The idea that the cosmological term, Lambda, should be a time dependent quantity in cosmology is a most natural one. It is difficult to conceive an expanding universe with a strictly constant vacuum energy density, namely one that has…
The primary focus of this dissertation is the study of the Casimir effect and the possibility that this phenomenon may serve as a mechanism to mediate higher dimensional stability, and also as a possible mechanism for creating a small but…
In this paper a possibility to accelerated the expansion of the large scale universe due to interacting varying Chaplygin gas of a specific form and a tachyonic matter is considered. A specific form of the potential and appropriate values…
If quantum fields exist in extra compact dimensions, they will give rise to a quantum vacuum or Casimir energy. That vacuum energy will manifest itself as a cosmological constant. The fact that supernova and cosmic microwave background data…
Different models of the cosmic substratum which pretend to describe the present stage of accelerated expansion of the Universe like the $\Lambda$CDM model or a Chaplygin gas, can be seen as special realizations of a holographic dark energy…
We consider a model where both dark energy and dark matter originate from the coupling of a scalar field with a non-conventional kinetic term to, both, a metric measure and a non-metric measure. An interacting dark energy/dark matter…
Cosmological hysteresis, has interesting and vivid implications in the scenario of a cyclic bouncy universe. This, purely thermodynamical in nature, is caused by the asymmetry in the equation of state parameter during expansion and…
If quantum fields exist in extra compact dimensions, they will give rise to a quantum vacuum or Casimir energy. That vacuum energy will manifest itself as a cosmological constant. The fact that supernova and cosmic microwave background data…
One approach in modern cosmology consists in supposing that dark matter and dark energy are different manifestations of a single `quartessential' fluid. Following such idea, this work presents a study of the evolution of perturbations of…
We construct a time dependent adjustment mechanism for the cosmological "constant" which could be at work in a late Friedmann-Robertson-Walker universe dominated by quintessence and matter. It makes use of a Brans-Dicke field that couples…
Quintessence theories for cosmic acceleration imbue dark energy with a non-trivial dynamics that offers hope in distinguishing the physical origin of the component. We review quintessence models with an emphasis on this dynamics and discuss…
Cosmologies with a Chaplygin gas have recently been explored with the objective of explaining the transition from a dust dominated epoch towards an accelerating expansion stage. We consider the hypothesis that the transition to the…
A new class of braneworld models displaying late-time phantom acceleration without resorting to a phantom fluid is presented. In this scenario expansion is fuelled by dark matter together with some effective dark energy capable of crossing…
We show that shape moduli in sub-millimeter extra dimensional scenarios, addressing the gauge hierarchy problem, can dominate the energy density of the universe today. In our scenario, the volume of the extra dimensions is stabilized at a…
The phase space analysis of cosmological parameters $\Omega_{\phi}$ and $\gamma_{\phi}$ is given. Based on this, the well-known quintessence cosmology is studied with an exponential potential $V(\phi)=V_{0}\exp(-\lambda\phi)$. Given…
The subject of our interest is an extended Chaplygin gas cosmology. In Literature a variety of cosmological models exist studying the behavior of the universe in the presence of the Chaplygin gas. From its initial form Chaplygin gas evolved…
Models where the accelerated expansion of our Universe is caused by a quintessence scalar field are reviewed. In the framework of high energy physics, the physical nature of this field is discussed and its interaction with ordinary matter…
Cosmological observations of the recent universe suggest that dark energy equation of state parameter $w$ is growing with time, departing from a cosmological constant for which $w=-1$. Standard quintessence models allow for a varying…