A family of toroidal diffusions with exact likelihood inference

Eduardo García-Portugués; Michael Sørensen

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arXiv · 2409.02705

A family of toroidal diffusions with exact likelihood inference

Eduardo García-Portugués·Michael Sørensen

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Abstract

We provide a class of diffusion processes for continuous time-varying multivariate angular data with explicit transition probability densities, enabling exact likelihood inference. The presented diffusions are time-reversible and can be constructed for any pre-specified stationary distribution on the torus, including highly-multimodal mixtures. We give results on asymptotic likelihood theory allowing one-sample inference and tests of linear hypotheses for $k$ groups of diffusions, including homogeneity. We show that exact and direct diffusion bridge simulation is possible too. A class of circular jump processes with similar properties is also proposed. Several numerical experiments illustrate the methodology for the circular and two-dimensional torus cases. The new family of diffusions is applied (i) to test several homogeneity hypotheses on the movement of ants and (ii) to simulate bridges between the three-dimensional backbones of two related proteins.

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Eduardo García-Portugués, Michael Sørensen. 2024-09-04. A family of toroidal diffusions with exact likelihood inference. https://arxiv.org/abs/2409.02705

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