Reciprocal Maximum Likelihood Degrees of Brownian Motion Tree Models

Abstract

We give an explicit formula for the reciprocal maximum likelihood degree of Brownian motion tree models. To achieve this, we connect them to certain toric (or log-linear) models, and express the Brownian motion tree model of an arbitrary tree as a toric fiber product of star tree models.

arXiv comment16 pages, 2 figures; v2: minor revision