Measuring the Equation-of-state of the Universe: Pitfalls and Prospects

Details Measuring the Equation-of-state of the Universe: Pitfalls and Prospects Measuring the Equation-of-state of the Universe: Pitfalls and Prospects

2001-12-21

arxiv.org/abs/astro-ph/0112526v1

Phys.Rev.D65:123003,2002

Astronomy and Astrophysics

Astrophysics

27 pages, 10 figures

Scientific paper

10.1103/PhysRevD.65.123003

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 degeneracy that makes it impossible to resolve well the value of w or its time-derivative with supernovae data. Here we consider standard practices, such as assuming priors that w is constant or greater than -1, and show that they also can lead to gross errors in estimating the true equation-of-state. We further consider combining measurements of the cosmic microwave background anisotropy and the Alcock-Paczynski test with supernovae data and find that the improvement in resolving the time-derivative of w is marginal, although the combination can constrain its present value perhaps to 20 percent uncertainty.

Affiliated with

Also associated with

No associations

Rating

Measuring the Equation-of-state of the Universe: Pitfalls and Prospects does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Measuring the Equation-of-state of the Universe: Pitfalls and Prospects, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Measuring the Equation-of-state of the Universe: Pitfalls and Prospects will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-49985