Related papers: What Do We Really Know About Cosmic Acceleration?
The present cosmic accelerating stage is discussed through a new kinematic method based on the Sunyaev- Zel'dovich effect (SZE) and X-ray surface brightness data from galaxy clusters. By using the SZE/X-ray data from 38 galaxy clusters in…
Recent discussions about supernova magnitude evolution have raised doubts about the robustness of the late-universe acceleration. In a previous letter, Huang did a null test of the cosmic acceleration by using a Parameterization based on…
Observational data for type Ia supernovae, shows that the expansion of the universe is accelerated. This accelerated expansion can be described by a cosmological constant or by dark energy models like quintessence. An interesting question…
Exploring the recent expansion history of the universe promises insights into the cosmological model, the nature of dark energy, and potentially clues to high energy physics theories and gravitation. We examine the extent to which precision…
We have observed the acceleration of the expansion of the universe. To explain this phenomenon, we usually introduce the dark energy (DE) which has a negative pressure or we need to modify the Einstein's equation to produce a term which is…
The energy conditions give upper bounds on the luminosity distance. We apply these upper bounds to the 192 essence supernova Ia data to show that the Universe had experienced accelerated expansion. This conclusion is drawn directly from the…
The kinematics and dynamic interpretation of the cosmological expansion is reviewed in a widely accessible manner with emphasis on the acceleration aspect. Virtually all the approaches that can in principle account for the accelerated…
The cosmic expansion history tests the dynamics of the global evolution of the universe and its energy density contents, while the cosmic growth history tests the evolution of the inhomogeneous part of the energy density. Precision…
Recent observations of distant supernovae imply, in defiance of expectations, that the universe growth is accelerating, contrary to what has always been assumed that the expansion is slowing down due to gravity. In this paper a…
The main argument that Universe is currently expanding is observed redshift increase by distance. However, this conclusion may not be correct, because cosmological redshift depends only on the scaling factors, the change in the size of the…
The acceleration of the expansion of the universe arises from unknown physical processes involving either new fields in high energy physics or modifications of gravitation theory. It is crucial for our understanding to characterize the…
I review the use of Type Ia supernovae (SNe Ia) in the 1998 discovery of the accelerating expansion of the Universe, as well as the subsequent use of SNe Ia to study the expansion history in more detail, determine the equation-of-state…
The discovery that the Universe is accelerating in its expansion has brought the basic concept of cosmic expansion into question. An analysis of the evolution of this concept suggests that the paradigm that was finally settled into prior to…
We probe the cosmic acceleration by using the recently released SNLS3 sample of 472 type Ia supernovae. Combining this type Ia supernovae dataset with the cosmic microwave background anisotropy data from the Wilkinson Microwave Anisotropy…
The possibility of an expanding decelerating Universe in the distant future is investigated in the context of a quintessence scalar field cosmology. Such a conceivable evolution is tested against SNe Ia and $H(z)$ cosmic chronometers data,…
In this essay, I present an alternative explanation for the cosmic acceleration which appears as a consequence of recent high redshift Supernova data. In the usual interpretation, this cosmic acceleration is explained by the presence of a…
Increasing astronomical evidence indicates that the expansion of the universe is accelerating. By simply solving Einstein equations we show in this letter that a wide class of generic quintessence models leading to eternal acceleration is…
The ability to map the cosmological expansion has developed enormously, spurred by the turning point one decade ago of the discovery of cosmic acceleration. The standard model of cosmology has shifted from a matter dominated, standard…
In this paper we review a part of the approaches that have been considered to explain the extraordinary discovery of the late time acceleration of the Universe. We discuss the arguments that have led physicists and astronomers to accept…
The observed late-time acceleration of the cosmic expansion constitutes a fundamental problem in modern theoretical physics and cosmology. In an attempt to weight the validity of a large number of dark energy models, I use the recent…