April 25th:
Prof. Asger Hobolth, Department of Mathematics, Aarhus University, Denmark: Phase-type distributions in mathematical population genetics: An emerging framework. (The talk is based on joint work with Iker Rivas-Gonzalez (Leipzig), Mogens Bladt (Copenhagen) and Andreas Futschik (Linz).)
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Meeting-ID: 280 519 2121
Passwort: 584190
Abstract:
A phase-type distribution is the time to absorption in a continuous- or discrete-time Markov chain. Phase-type distributions can be used as a general framework to calculate key properties of the standard coalescent model and many of its extensions. Here, the ‘phases’ in the phase-type distribution correspond to states in the ancestral process. For example, the time to the most recent common ancestor and the total branch length are phase-type distributed. Furthermore, the site frequency spectrum follows a multivariate discrete phase-type distribution and the joint distribution of total branch lengths in the two-locus coalescent-with-recombination model is multivariate phase-type distributed. In general, phase-type distributions provide a powerful mathematical framework for coalescent theory because they are analytically tractable using matrix manipulations. The purpose of this talk is to explain the phase-type theory and demonstrate how the theory can be applied to derive basic properties of coalescent models. These properties can then be used to obtain insight into the ancestral process, or they can be applied for statistical inference.