Extinction time of the logistic process


Abstract in English

The logistic birth and death process is perhaps the simplest stochastic population model that has both density-dependent reproduction, and a phase transition, and a lot can be learned about the process by studying its extinction time, $tau_n$, as a function of system size $n$. A number of existing results describe the scaling of $tau_n$ as $ntoinfty$, for various choices of reproductive rate $r_n$ and initial population $X_n(0)$ as a function of $n$. We collect and complete this picture, obtaining a complete classification of all sequences $(r_n)$ and $(X_n(0))$ for which there exist rescaling parameters $(s_n)$ and $(t_n)$ such that $(tau_n-t_n)/s_n$ converges in distribution as $ntoinfty$, and identifying the limits in each case.

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