2015/10/21 by Alsmeyer, Gerold, Dyszewski, Piotr
#60E10 #60H25 #FOS: Mathematics #Probability (math.PR)
paper · doi:10.48550/arxiv.1510.06451
For a given random sequence (C,T1,T2,…) with nonzero C and a.s. finite number of nonzero Tk, the nonhomogeneous smoothing transform S maps the law of a real random variable X to the law of ∑k≥ 1TkXk+C, where X1,X2,… are independent copies of X and also independent of (C,T1,T2,…). This law is a fixed point of S if the stochastic fixed-point equation (SFPE) X\stackreld=∑k≥ 1TkXk+C holds true, where \stackreld= denotes equality in law. Under suitable conditions including 𝔼 C=0, S possesses a unique fixed point within the class of centered distributions, called the canonical solution to the above SFPE because it can be obtained as a certain martingale limit in an associated weighted branching model. The present work provides conditions on (C,T1,T2,…) such that the canonical solution exhibits right and/or left Poisson tails and the abscissa of convergence of its moment generating function can be determined. As a particular application, the right tail behavior of the Quicksort distribution is found.