Explicit solution of the general multitype Lamperti representation

Construct an explicit expression for the pathwise solution of the multitype Lamperti stochastic differential equation as a function of the driving Lévy processes in dimensions beyond the one-type case and beyond the 2-cyclic two-type case.

Background

A Lamperti representation for multitype branching processes expresses each component of the process through Lévy processes evaluated at integrated population times. Although existence and pathwise uniqueness are known, an explicit representation of the solution in terms of the driving Lévy processes is generally unavailable.

The paper derives such an expression in the 2-cyclic two-type configuration. The corresponding problem for general multitype branching processes remains unresolved.

References

It is also observed in the same paper that no expression of the solution as a function of $X$ is known, except in the case $d=1$.

— On conservativity of multitype continuous-state branching processes  (2610.23649 - Chaumont et al., 16 Oct 2026) in Section 3.2, Further results for 2-types processes