Variance of the Internal Profile in Suffix Trees
  The precise analysis of the variance of the profile of a suffix tree has been a longstanding open problem. We analyze three regimes of the asymptotic growth of the variance of the profile of a suffix tree built from a randomly generated binary string, in the nonuniform case. We utilize combinatorics on words, singularity analysis, and the Mellin transform. 
Jeffrey Gaither and Mark Daniel Ward
cs.DS