A kinematic method to probe cosmic acceleration

作者：Barboza Edesio M Jr^*; Carvalho F C

来源：Physics Letters B, 2012, 715(1-3): 19-24.

DOI：10.1016/j.physletb.2012.07.042

We propose a method to map the cosmological evolution of the main kinematic parameters H, q and j from observational data. Unlike the traditional approach, the methodology here discussed provides constraints on the kinematic parameters not only at z = 0 but also at any value of the redshift parameter. By choosing the scale factor as expansion variable in order to avoid the series convergence and truncation problems, we perform a Taylor expansion of the luminosity distance around an arbitrary (a) over tilde and use current type Ia supernovae data to estimate the values of H, q and j for 0.41 less than or similar to (a) over tilde <= 1 (0 <= z <= 1.4). We show that the transition from a decelerated phase to an accelerating one occurs in the range 0.4 less than or similar to z less than or similar to 0.9 and that for z greater than or similar to 0.5 the value of j = 1 is ruled out in 2 sigma confidence level.

• 出版日期2012-8-29