Reconstruct the Distance Duality Relation by Gaussian Process
  In this letter, the distance-duality (DD) relation is reconstructed by
Gaussian process (GP) which is cosmological model-independent. Generally, the
GP plays two important roles. One is to shape the $\eta$ tendency which denotes
the deviation from the DD relation, the other one is to produce the
luminosity-distance (LD, $D_{L}$) and the angular-diameter-distance (ADD,
$D_{A}$) data at the same redshift. The shapes of $\eta$ are given out based on
SNe Ia (Type Ia supernovae) data with different light-curve fitters (including
MLCS2K2 and SALT2) and ADD data with different galaxy cluster morphologies
(including the elliptical $\beta$ and spherical $\beta$ models). The data
related to MLCS2K2 light-curve fitter have higher values of $\eta$ compared to
that related to the SALT2 light-curve fitter. As for the morphology of galaxy
cluster, the DD relation is favored by the elliptical one.
