English

On the infinite divisibility of inverse Beta distributions

Probability 2014-05-26 v2

Abstract

We show that all negative powers B_{a,b}^-{s} of the Beta distribution are infinitely divisible. The case b<1 follows by complete monotonicity, the case b > 1, s > 1 by hyperbolically complete monotonicity and the case b > 1, s < 1 by a L\'evy perpetuity argument involving the hypergeometric series. We also observe that B_{a,b}^{-s} is self-decomposable whenever 2a + b + s + bs > 1, and that it is not always a generalized Gamma convolution. On the other hand, we prove that all negative powers of the Gamma distribution are generalized Gamma convolutions, answering to a recent question of L. Bondesson.

Keywords

Cite

@article{arxiv.1405.4176,
  title  = {On the infinite divisibility of inverse Beta distributions},
  author = {Pierre Bosch and Thomas Simon},
  journal= {arXiv preprint arXiv:1405.4176},
  year   = {2014}
}