Limit Theorems for Random Walks Conditioned to Stay Positive
Keener, Robert W.
Ann. Probab., Tome 20 (1992) no. 4, p. 801-824 / Harvested from Project Euclid
Let $\{S_n\}$ be a random walk on the integers with negative drift, and let $A_n = \{S_k \geq 0, 1 \leq k \leq n\}$ and $A = A_\infty$. Conditioning on $A$ is troublesome because $P(A) = 0$ and there is no natural sigma-field of events "like" $A. A$ natural definition of $P(B\mid A)$ is $\lim_{n\rightarrow\infty}P(B\mid A_n)$. The main result here shows that this definition makes sense, at least for a large class of events $B$: The finite-dimensional conditional distributions for the process $\{S_k\}_{k\geq 0}$ given $A_n$ converge strongly to the finite-dimensional distributions for a measure $\mathbf{Q}$. This distribution $\mathbf{Q}$ is identified as the distribution for a stationary Markov chain on $\{0,1,\ldots\}$.
Publié le : 1992-04-14
Classification:  Large deviations,  Markov chains,  conditional limit theorems,  quasistationary distributions,  60J15,  60G50
@article{1176989807,
     author = {Keener, Robert W.},
     title = {Limit Theorems for Random Walks Conditioned to Stay Positive},
     journal = {Ann. Probab.},
     volume = {20},
     number = {4},
     year = {1992},
     pages = { 801-824},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1176989807}
}
Keener, Robert W. Limit Theorems for Random Walks Conditioned to Stay Positive. Ann. Probab., Tome 20 (1992) no. 4, pp.  801-824. http://gdmltest.u-ga.fr/item/1176989807/