Universal Behavior of a Research Productivity Index
  Indexes that account for good representations of an individual's productivity are theme of major importance for the evaluation and comparison among researchers. Recently, a new index was proposed combining productivity with impact such that a researcher with index h has h papers with at least h citations. A drawback of this is the sensitivity to the research field. Here we propose a new index (hI) that accounts for the coauthorship effect. The statistics of h and hI are presented for Brazilian research. We have found a universal curve for different disciplines, allowing a comparison among scientists of different research areas. 
Pablo Diniz Batista, Monica Guimaraes Campiteli, Osame Kinouchi and   Alexandre Souto Martinez