Martingale convergence and the stopped branching random walk
Martingale convergence and the stopped branching random walk
复制标题
鞅收敛和停止分支随机游走
DOI:
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发表时间:
2000
期刊:
影响因子:
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通讯作者:
A. Kyprianou
中科院分区:
文献类型:
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作者:
A. Kyprianou
Abstract. We discuss the construction of stopping lines in the branching random walk and thus the existence of a class of supermartingales indexed by sequences of stopping lines. Applying a method of Lyons (1997) and Lyons, Pemantle and Peres (1995) concerning size biased branching trees, we establish a relationship between stopping lines and certain stopping times. Consequently we develop conditions under which these supermartingales are also martingales. Further we prove a generalization of Biggins' Martingale Convergence Theorem, Biggins (1977a) within this context.