Positivity bounds on parton distributions at large N_c

Abstract

Positivity bounds for twist-two parton distributions in multicolored QCD are stronger than their analogs at finite $N_c$. They include the enhanced large $N_{c}$ version of Soffer inequality. These bounds are compatible with the DGLAP evolution to higher normalization points.Comment: 7 pages, to be published in the proceedings of "The Phenomenology of Large Nc QCD" workshop, 9-11 January 2002, Arizona State University, Temp