Transition redshift from the V-reconstruction method

Wojciech Czaja; Marek Szydlowski; Adam Krawiec

paper

Transition redshift from the V-reconstruction method

arXiv:astro-ph/0404612

Abstract

We show the effectiveness of using the procedure of the potential reconstruction (the V-method) in the estimation of the transition redshift corresponding to switch from deceleration to acceleration phase of the Universe. We investigate the FRW models with dark energy by applying the particle-like description of their dynamics. In this picture the evolution of the universe is represented by motion of a fictitious particle in the one-dimensional potential $V (a)$ or V(z) $w h er e$ a $i s t h esc a l e f a c t or an d$ z $i s t h er e d s hi f t . T h e V - m e t h o d so l v es t h e in v er se p r o b l e m w h er e w er eco n s t r u c tt h e p o t e n t ia l f u n c t i o n f r o m e m p i r i c a l d a t a . W e u se t h e R i esse t a l .^{'} s g o l d an d g o l d + s i l v er s am pl eso f S N I a d a t ain t hi sr eco n s t r u c t i o n . I n t h es am e f r am e w or k w eo b t ainb o t h t h ees t ima t eso f t h e f or m o f t h ee q u a t i o n o f s t a t e f or d a r k e n er g y an d t h e t r an s i t i o n r e d s hi f t . W eo b t ain t ha tt r an s i t i o n r e d s hi f t i s$ 0.38_{-0.07}^{+0.10} $(g o l d s u b se t) an d$ 0.37_{-0.07}^{+0.06} $(g o l d + s i l v er s am pl e) w h e n t h e l in e a r m o d e l o f d a r k e n er g y ($ w(z)=w_{0} + w_{1}z $) an d$ Ω_{m,0}=0.3$ are assumed. We compare the estimation of transition redshift with the Riess et al. results. The V-method also alows us to find the value of Hubble function at the moment of transition.

RevTeX4, 6 pages, 2 figures