More on hypergeometric Lévy processes

Kuznetsov and co-authors in 2011‒14 introduced the family of hypergeometric Levy processes . They appear naturally in the study of fluctuations of stable processes when one analyses stable processes through the theory of positive self-similar Markov processes. Hypergeometric Levy processes are defined through their characteristic exponent, which, as a complex-valued function, has four independent parameters. In 2014 it was shown that the definition of a hypergeometric Levy process could be taken to include a greater range of the aforesaid parameters than originally specified. In this short article, we push the parameter range even further.