2017/08/10 by Beghin, Luisa, Ricciuti, Costantino
#26A33 #60G51 #60G52 #FOS: Mathematics #Probability (math.PR)
paper · doi:10.48550/arxiv.1708.03159
Additive processes are obtained from Lévy ones by relaxing the condition of stationary increments, hence they are spatially (but not temporally) homogeneous. By analogy with the case of time-homogeneous Markov processes, one can define an infinitesimal generator, which is, of course, a time-dependent operator. Additive versions of stable and Gamma processes have been considered in the literature. We introduce here time-inhomogeneous generalizations of the well-known geometric stable process, defined by means of time-dependent versions of fractional pseudo-differential operators of logarithmic type. The local Lévy measures are expressed in terms of Mittag-Leffler functions or H-functions with time-dependent parameters.