On the accelerated expansion of the cosmos

Details On the accelerated expansion of the cosmos On the accelerated expansion of the cosmos

2010-12-22

arxiv.org/abs/1012.4906v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

7 pages, 3 figures, invited talk given at the School on Nuclear Astrophysics, Erice 2010

Scientific paper

We present a short (and necessarily incomplete) review of the evidence for the accelerated expansion of the Universe. The most direct probe of acceleration relies on the detailed study of supernovae (SN) of type Ia. Assuming that these are standardizable candles and that they fairly sample a homogeneous and isotropic Universe, the evidence for acceleration can be tested in a model- and calibration-independent way. Various light-curve fitting procedures have been proposed and tested. While several fitters give consistent results for the so-called Constitution set, they lead to inconsistent results for the recently released SDSS SN. Adopting the SALT fitter and relying on the Union set, cosmic acceleration is detected by a purely kinematic test at 7 sigma when spatial flatness is assumed and at 4 sigma without assumption on the spatial geometry. A weak point of the described method is the local set of SN (at z < 0.2), as these SN are essential to anchor the Hubble diagram. These SN are drawn from a volume much smaller than the Hubble volume and could be affected by local structure. Without the assumption of homogeneity, there is no evidence for acceleration, as the effects of acceleration are degenerate with the effects of inhomogeneities. Unless we sit in the centre of the Universe, such inhomogeneities can be constrained by SN observations by means of tests of the isotropy of the Hubble flow.

Affiliated with

Also associated with

No associations

Rating

On the accelerated expansion of the cosmos 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 On the accelerated expansion of the cosmos, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the accelerated expansion of the cosmos will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-581988