Possible evidences from H(z) parameter data for physics beyond ΛCDM

Abstract

We analyze $H\left(z\right)$ parameter data with some conditions by using Lagrange mean value theorem in Calculus. We find that: (1) there exists decelerated phase at 1 $\sigma$ confidence level in the redshift range $(0.38,0.59)$; (2) the equation of state of dark energy may be less than $-1$ at 1 $\sigma$ confidence level at some redshifts in the redshift range $(1.3,1.53)$; (3) there exists accelerated phase at 1 $\sigma$ confidence level in the redshift range $(1.037,1.944)$. These results may provide possible evidences for physics beyond $\Lambda$CDM.