Photometric Redshifts with Copula Entropy
Jian Ma
In this paper we propose to apply copula entropy (CE) to photometric
redshifts. CE is used to measure the correlations between photometric
measurements and redshifts and then the measurements associated with high CEs
are selected for predicting redshifts. We verified the proposed method on the
SDSS quasar data. Experimental results show that the accuracy of photometric
redshifts is improved with the selected measurements compared to the results
with all the measurements used in the experiments, especially for the samples
with high redshifts. The measurements selected with CE include luminosity
magnitude, the brightness in ultraviolet band with standard deviation, and the
brightness of the other four bands. Since CE is a rigorously defined
mathematical concept, the models such derived is interpretable.