Wright function in the solution to the Kolmogorov equation of the Markov branching process with geometric reproduction of particles*

The topic of this work is the supercritical geometric reproduction of particles in the model of a Markov branching process. The solution to the Kolmogorov equation is expressed by the Wright function. The series expansion of this representation is obtained by the Lagrange inversion method. The asymptotic behavior is described by using two different equivalent forms for the Laplace transform. They include the computation of the limit distribution and its moments. The exact formula for the asymptotic density is written in terms of the reduced Wright function. In particular, when the ultimate extinction probability q = 1/2, the density of the limit random variable is given by the incomplete gamma function.