title: Exact formulas for the variance of several balance indices under the Yule model.
abstract: One of the main applications of balance indices is in tests of nullmodels of evolutionary processes. The knowledge of an exact formula for a statistic of a balance index, holding for any number n of leaves, is necessary in order to use this statistic in tests of this kind involving trees of any size. In this paper we obtain exact formulas for the variance under the Yule model of the Sackin, the Colless and the total cophenetic indices of binary rooted phylogenetic trees with n leaves.
authors.affiliation: Department of Mathematics and Computer Science, University of the Balearic Islands, 07122 , Palma, Spain, gabriel.cardona@uib.es.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Cardona
authors.forename: Arnau
authors.initials: A
authors.lastname: Mir
authors.forename: Francesc
authors.initials: F
authors.lastname: Rosselló
mesh_terms: D005075:Biological Evolution; D008957:Models, Genetic; D010802:Phylogeny