Constructing a cosmological model-independent Hubble diagram of type Ia
  supernovae with cosmic chronometers
  We apply two methods, namely the Gaussian processes and the non-parametric
smoothing procedure, to reconstruct the Hubble parameter $H(z)$ as a function
of redshift from 15 measurements of the expansion rate obtained from age
estimates of passively evolving galaxies. These reconstructions enable us to
derive the luminosity distance to a certain redshift $z$, calibrate the
light-curve fitting parameters accounting for the (unknown) intrinsic magnitude
of type Ia supernova (SNe Ia) and construct cosmological model-independent
Hubble diagrams of SNe Ia. In order to test the compatibility between the
reconstructed functions of $H(z)$, we perform a statistical analysis
considering the latest SNe Ia sample, the so-called JLA compilation. We find
that, for the Gaussian processes, the reconstructed functions of Hubble
parameter versus redshift, and thus the following analysis on SNe Ia
calibrations and cosmological implications, are sensitive to prior mean
functions. However, for the non-parametric smoothing method, the reconstructed
functions are not dependent on initial guess models, and consistently require
high values of $H_0$, which are in excellent agreement with recent measurements
of this quantity from Cepheids and other local distance indicators.
