An empirical investigation of the g-index for 26 physicists in   comparison with the h-index, the A-index, and the R-index
  Hirsch has introduced the h-index to quantify an individual's scientific research output by the largest number h of a scientist's papers that received at least h citations. In order to take into account the highly skewed frequency distribution of citations, Egghe proposed the g-index as an improvement of the h-index. I have worked out 26 practical cases of physicists from the Institute of Physics at Chemnitz University of Technology and compare the h and g values. It is demonstrated that the g-index discriminates better between different citation patterns. This can also be achieved by evaluating Jin's A-index which reflects the average number of citations in the h-core and interpreting it in conjunction with the h-index. h and A can be combined into the R-index to measure the h-core's citation intensity. I have also determined the A and R values for the 26 data sets. For a better comparison, I utilize interpolated indices. The correlations between the various indices as well as with the total number of papers and the highest citation counts are discussed. The largest Pearson correlation coefficient is found between g and R. Although the correlation between g and h is relatively strong, the arrangement of the data set is significantly different, depending on whether they are put into order according to the values of either h or g. 
Michael Schreiber