Abstract:
For critical branching processes in random environment, under some slight restrictions, the following inequalities for the tails of the extinction time distribution are proved:
\begin{equation}
c_1/\sqrt n\le\mathbf P(T>n)\le c_2/\sqrt n.
\end{equation}
In the case of fractional linear generating functions, (1) is replaced by
$$
\mathbf P(T>n)\sim c/\sqrt n,\qquad n\to\infty.
$$