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Related papers: Probing Dark Energy with SNAP

200 papers

Two new one-parameter tracking behavior dark energy representations $\omega=\omega_0/(1+z)$ and $\omega=\omega_0 e^{z/(1+z)}/(1+z)$ are used to probe the geometry of the Universe and the property of dark energy. The combined type Ia…

Astrophysics · Physics 2009-11-10 Yungui Gong , Yuan-Zhong Zhang

Determining the properties of the dark components of the universe remains one of the outstanding challenges in cosmology. We explore how upcoming CMB anisotropy measurements, galaxy power spectrum data, and supernova (SN) distance…

Astrophysics · Physics 2009-08-18 Wayne Hu , Daniel J. Eisenstein , Max Tegmark , Martin White

Understanding the origin of the accelerated expansion of the Universe poses one of the greatest challenges in physics today. Lacking a compelling fundamental theory to test, observational efforts are targeted at a better characterization of…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-28 Tracy Holsclaw , Ujjaini Alam , Bruno Sanso , Herbert Lee , Katrin Heitmann , Salman Habib , David Higdon

We explore various pitfalls and challenges in determining the equation-of-state (w) of dark energy component that dominates the universe and causes the current accelerated expansion. We demonstrated in an earlier paper the existence of a…

Astrophysics · Physics 2009-09-15 Irit Maor , Ram Brustein , Jeff McMahon , Paul J. Steinhardt

Observations of high-redshift supernovae indicate that the universe is accelerating. Here we present a {\em model-independent} method for estimating the form of the potential $V(\phi)$ of the scalar field driving this acceleration, and the…

Astrophysics · Physics 2009-10-31 Tarun Deep Saini , Somak Raychaudhury , Varun Sahni , A. A. Starobinsky

We study the utility of wavelets for detecting the redshift evolution of the dark energy equation of state w(z) from the combination of supernovae, CMB and BAO data. We show that local features in w, such as bumps, can be detected…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-20 Alireza Hojjati , Levon Pogosian , Gong-Bo Zhao

In the search for the nature of dark energy most cosmological probes measure simple functions of the expansion rate. While powerful, these all involve roughly the same dependence on the dark energy equation of state parameters, with…

Astrophysics · Physics 2009-11-10 Eric V. Linder

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…

Astrophysics · Physics 2009-11-10 Eric V. Linder

Observations of high-redshift Type Ia supernovae (SNe Ia) have provided strong evidence that the dark energy is real, and making further accurate observations of high-redshift SNe Ia is the most promising way to probe the nature of the dark…

Astrophysics · Physics 2007-05-23 David Branch , Saul Perlmutter , E. Baron , Peter Nugent

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 lensing convergence power spectrum. Some…

Astrophysics · Physics 2009-11-06 Dragan Huterer

The recent robust and homogeneous analysis of the world's supernova distance-redshift data, together with cosmic microwave background and baryon acoustic oscillation data, provides a powerful tool for constraining cosmological models. Here…

Future redshift-drift measurements (also known as Sandage-Loeb signal) will be crucial to probe the so called "redshift desert", thus providing a new tool for cosmological studies. In this paper we quantify the ability of a future…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Matteo Martinelli , Stefania Pandolfi , C. J. A. P. Martins , P. E. Vielzeuf

We present a simple mechanism which can mimic dark energy with an equation of state w < -1 as deduced from the supernova data. We imagine that the universe is accelerating under the control of a quintessence field, which is moving up a very…

Astrophysics · Physics 2009-11-11 Csaba Csaki , Nemanja Kaloper , John Terning

New precision in measuring extragalactic distances using supernovae has confirmed with high probability an accelerating increase in redshift with distance. This has been interpreted as implying the existence of dark energy in an expanding…

Astrophysics · Physics 2007-05-23 William Q. Sumner

Number counts of galaxy clusters offer a very promising probe of the Dark Energy (DE) equation-of-state parameter, $w$. The basic goal is to measure abundances of these objects as a function of redshift, compare this to a theoretical…

Astrophysics · Physics 2009-09-29 M. Davis , B. F. Gerke , A. L. Coil , M. C. Cooper , R. Yan , J. A. Newman , S. M. Faber , D. Koo , P. Guhathakurta

Despite two decades of tremendous experimental and theoretical progress, the riddle of the accelerated expansion of the Universe remains to be solved. On the experimental side, our understanding of the possibilities and limitations of the…

The strongest evidence for dark energy comes presently from geometric techniques such as the supernova distance-redshift relation. By combining the measured expansion history with the Friedmann equation one determines the energy density and…

Astrophysics · Physics 2008-11-26 Edmund Bertschinger

The presence of dark energy in our universe is causing space to expand at an accelerating rate. As a result, over the next approximately 100 billion years, all stars residing beyond the Local Group will fall beyond the cosmic horizon and…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-15 Dan Hooper

The current observations are usually explained by an accelerating expansion of the present universe. However, with the present quality of the supernovae Ia data, the allowed parameter space is wide enough to accommodate the decelerating…

Astrophysics · Physics 2009-11-07 R. G. Vishwakarma

The true nature of dark energy remains unclear: It is either a strange fluid in the Universe, with a negative effective pressure, or a breakdown in General Relativity on large scales. This question can only be answered through a suite of…

Astrophysics · Physics 2007-05-23 Robert Nichol