New Constraints on Dark Energy
@article{Melchiorri2004NewCO, title={New Constraints on Dark Energy}, author={Alessandro Melchiorri}, journal={arXiv: Astrophysics}, year={2004} }
New Cosmic Microwave Background, Galaxy Clustering and Supernovae type Ia data are increasingly constraining the dark energy component of our Universe. While the cosmological constant scenario remains consistent with these new tight constraints, the data does not rule out the possibility that the equation of state parameter is less than -1.
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References
SHOWING 1-10 OF 68 REFERENCES
Are Chaplygin gases serious contenders for the dark energy
- Physics
- 2003
We study the implications on both background and perturbation evolution of introducing a Chaplygin gas component in the universe's ingredients. We perform likelihood analyses using wide-ranging,…
Weak lensing and dark energy
- Physics
- 2002
We study the power of upcoming weak lensing surveys to probe dark energy. Dark energy modifies the distance-redshift relation as well as the matter power spectrum, both of which affect the weak…
Domain walls as dark energy
- Physics
- 2003
The possibility that the energy density of the Universe is dominated by a network of low-tension domain walls provides an alternative to the commonly discussed cosmological constant and scalar-field…
Cosmic Concordance and Quintessence
- Physics
- 2000
We present a comprehensive study of the observational constraints on spatially flat cosmological models containing a mixture of matter and quintessence—a time-varying, spatially inhomogeneous…
Type Ia Supernova Discoveries at z > 1 from the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution
- Physics
- 2004
We have discovered 16 Type Ia supernovae (SNe Ia) with the Hubble Space Telescope (HST) and have used them to provide the first conclusive evidence for cosmic deceleration that preceded the current…
Cosmological imprint of an energy component with general equation of state
- Physics
- 1998
We examine the possibility that a significant component of the energy density of the Universe has an equation of state different from that of matter, radiation, or cosmological constant ({Lambda} ).…
First-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
- Physics
- 2003
WMAP precision data enable accurate testing of cosmological models. We find that the emerging standard model of cosmology, a flat Λ-dominated universe seeded by a nearly scale-invariant adiabatic…
The Cosmological Constant and Dark Energy
- Physics
- 2003
Physics invites the idea that space contains energy whose gravitational effect approximates that of Einstein's cosmological constant, Lambda: nowadays the concept is termed dark energy or…
Dark Matter and Dark Energy
- Physics
- 2004
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…