On the determination of the deceleration parameter from Supernovae data

J. -M. Virey; P. Taxil; A. Tilquin; A. Ealet; C. Tao; D. Fouchez

doi:10.1103/physrevd.72.061302

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On the determination of the deceleration parameter from Supernovae data

J. -M. Virey·P. Taxil·A. Tilquin·A. Ealet·C. Tao·D. Fouchez

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Abstract

Supernovae searches have shown that a simple matter-dominated and decelerating universe should be ruled out. However a determination of the present deceleration parameter $q_0$ through a simple kinematical description is not exempt of possible drawbacks. We show that, with a time dependent equation of state for the dark energy, a bias is present for $q_0$ : models which are very far from the so-called Concordance Model can be accommodated by the data and a simple kinematical analysis can lead to wrong conclusions. We present a quantitative treatment of this bias and we present our conclusions when a possible dynamical dark energy is taken into account.

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J. -M. Virey, P. Taxil, A. Tilquin, A. Ealet, C. Tao, D. Fouchez. 2005-02-08. On the determination of the deceleration parameter from Supernovae data. https://doi.org/10.1103/physrevd.72.061302

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