Nonparametric reconstruction of dynamical dark energy via observational Hubble parameter

We study the power of current and future observational Hubble parameter data (OHD) on nonparametric estimations of the dark energy equation of state (EoS), w(z). We propose a new method by conjunction of principal component analysis and the goodness of fit criterion to reconstruct w(z), ensuring the sensitivity and reliability of the extraction of features in the EoS. We also give a new error model to simulate future OHD data, to forecast the power of future OHD on the EoS reconstruction. The result shows that current OHD, despite their lesser quantity, give not only a similar power of reconstruction of dark energy compared to the result given by type Ia supernovae, but also extend the constraint on w(z) up to redshift z similar or equal to 2. Additionally, a reasonable forecast of future data in greater quantity and better quality greatly enhances the reconstruction of dark energy.