Sharp errors for point-wise Poisson approximations in mixing processes
Sharp errors for point-wise Poisson approximations in mixing processes
复制标题
混合过程中逐点泊松近似的尖锐误差
DOI:
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发表时间:
2008
期刊:
影响因子:
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通讯作者:
N. Vergne
中科院分区:
文献类型:
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作者:
M. Abadi;N. Vergne
We describe the statistics of the number of occurrences of a string of symbols in a stochastic process: taking a string A of length n, we prove that the number of visits to A up to time t, denoted by Nt, has approximately a Poisson distribution. We provide a sharp error for this approximation. In contrast to previous works which present uniform error terms based on the total variation distance, our error is point-wise. As a byproduct we obtain that all the moments of Nt are finite. Moreover, we obtain explicit approximations for all of them. Our result holds for processes that verify the ϕ-mixing condition. The error term is explicitly expressed as a function of the rate function ϕ and is easily computable.