Constraining the dark energy statefinder hierarchy in a kinematic
  approach
  In the present work, we have adopted a kinematic approach for constraining
the extended null diagnostic of concordance cosmology, known as the statefinder
hierarchy. A Taylor series expansion of the Hubble parameter has been utilised
for the reconstruction. The coefficients of the Taylor series expansion are
related to the kinematical parameters like the deceleration parameter,
cosmological jerk parameter etc. The present values of the kinematical
parameters are constrained from the estimated values of those series
coefficients. A Markov chain Monte Carlo analysis has been carried out using
the observational measurements of Hubble parameter at different redshifts, the
distance modulus data of type Ia supernovae and baryon acoustic oscillation
data to estimate the coefficient of series expansion of the Hubble parameter.
The parameters in the statefinder diagnostic are related to the kinematical
parameters. The statefinder diagnostic can form sets of hierarchy according to
the order of the kinematical parameters. The present values of statefinder
parameters have been constrained. The first set in the statefinder hierarchy
allows $\Lambda$CDM to be well within the 1$\sigma$ confidence region, whereas
the second set is in disagreement with the corresponding $\Lambda$CDM values at
more than 1$\sigma$ level. Another dark energy diagnostic, namely the
$Om$-parameters, is found to be consistent with concordance cosmology.
