Matsumoto-Yor processes on Jordan algebras
Reda Chhaibi, Manon Defosseux
TL;DR
The paper generalizes Matsumoto–Yor processes to Euclidean Jordan algebras, proving that a generalized geometric 2M-X Matsumoto–Yor process remains Markov on symmetric cones and satisfies a Dufresne-type identity. It develops a discrete Rider–Valkó–type block construction in Jordan-algebra settings, establishes intertwining-based proofs of the Matsumoto–Yor property and a discrete inverse-Wishart limit, and then passes to continuous time via a Stroock–Varadhan invariance principle on Lie groups, yielding continuous-time analogues. Special cases recover known matrix-valued results and yield new phenomena for the Lorentz cone and other symmetric cones, including potential octonionic extensions. The approach hinges on Jordan-algebra quadratic representations and intertwinings, unifying probabilistic and representation-theoretic viewpoints and offering a framework for perpetuity-type identities on symmetric cones with rich algebraic structure.
Abstract
The process $(\int_0^t e^{2b_s-b_t}\, ds\ ;\ t\ge 0)$, where $b$ is a real Brownian motion, is known as the geometric 2M-X Matsumoto--Yor process. Remarkably, it enjoys the Markov property. We provide a generalization of this process in the context of Jordan algebras, and we prove the Markov property for this generalization. Our Markov process occurs as a limit of discrete-time AX+B Markov chains on the cone of squares whose invariant probability measures classically yield a Dufresne-type identity for a perpetuity. In particular, the paper provides a generalization to any symmetric cone of the matrix--valued generalization of the Matsumoto--Yor process and Dufresne identity initially developed by Rider--Valkó.
