Symmetric infinitely divisible processes with sample paths in Orlicz spaces and absolute continuity of infinitely divisible processes

We give necessary and sufficient conditions under which a symmetric measurable infinitely divisible process has sample paths in an Orlicz space Lψ with a function ψ satisfying the Δ2 condition and, as an application, obtain necessary and sufficient conditions for a symmetric infinitely divisible process to have a version with absolutely continuous paths.