Offspring probability generating function

Definition taught in Galton–Watson branching, part of Stochastic processes

Offspring probability generating function

Type Definition
Taught in Galton–Watson branching
Part Stochastic processes

The offspring probability generating function is

f(s)=\mathbb{E}(s^{\xi})=\sum_{k\ge 0}p_k s^k, \qquad 0\le s\le 1.

It satisfies f(1)=1. If the mean is finite, f'(1-)=m. If \mathbb{E}[\xi(\xi-1)] is finite, f''(1-)=\mathbb{E}[\xi(\xi-1)].

Used in

See also

Extinction criterion

Glossary and index