Kinematic constraints to the transition redshift from supernovae type Ia union data

2008/11/14 by J. V. Cunha
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Gamma-ray bursts and supernovae #astro-ph

paper · pdf · doi:10.1103/physrevd.79.047301

published as Phys.Rev.D79:047301,2009 · 10 pages, 4 figures, 1 table

arxiv created 2008/11/14 · openalex publication_date 2009/02/27 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

The kinematic approach to cosmological tests provides direct evidence to the present accelerating stage of the Universe that does not depend on the validity of general relativity, as well as on the matter-energy content of the Universe. In this context, we consider here a linear two-parameter expansion for the decelerating parameter, q(z)=q₀+q₁z, where q₀ and q₁ are arbitrary constants to be constrained by the union supernovae data. By assuming a flat Universe we find that the best fit to the pair of free parameters is (q₀,q₁)=(\ensuremath-0.73,1.5) whereas the transition redshift is z_t=0.49_\ensuremath-0.07^+0.14(1\ensuremathσ) \genfrac0+0.54\ensuremath-0.12(2\ensuremathσ). This kinematic result is in agreement with some independent analyses and more easily accommodates many dynamical flat models (like \ensuremathΛCDM).

Citations

• Cosmological implications of APM 08279+5255, an old quasar at z = 3.91
• Dynamics of dark energy
• Cosmological consequences of a rolling homogeneous scalar field
• Constraining the equation of state of the Universe from distant Type Ia supernovae and cosmic microwave background anisotropies
• Reconstruction of the deceleration parameter and the equation of state of dark energy