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arXiv 1505.04425math.PR
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精确尾渐近性的核方法--四分之一平面上的随机游动

A Kernel Method for Exact Tail Asymptotics --- Random Walks in the Quarter Plane

Hui Li, Yiqiang Q. Zhao

摘要:

本文提出了一种核方法来研究四分之一平面上随机游动到邻域的精确尾渐近性。这是一种二维方法,不需要确定未知的生成函数。相反,在渐近分析和Tauberian定理,我们表明,信息的位置占主导地位的奇异性或奇异性和详细的渐近性质在一个占主导地位的奇异性是足够的确切的尾部渐近行为的边缘分布,也为联合概率沿坐标方向。我们提供的所有细节,不仅是一个“典型”的情况下,一个未知的生成函数的情况下,一个单一的主导奇点,但也为所有的非典型情况下,还没有被研究过。对于典型的情形,共发现了四种类型的精确尾渐近性,这在文献中已有报道。我们还证明了在收敛圆上,一个未知的母函数可能有两个而不是一个主导奇点,这可能导致一个新的周期现象。最后给出了应用该核方法的实例。本文可以认为是对已有思想的系统总结和延伸,其中也包含了新的有趣的研究成果。

英文摘要:

In this paper, we propose a kernel method for exact tail asymptotics of a random walk to neighborhoods in the quarter plane. This is a two-dimensional method, which does not require a determination of the unknown generating function(s). Instead, in terms of the asymptotic analysis and a Tauberian-like theorem, we show that the information about the location of the dominant singularity or singularities and the detailed asymptotic property at a dominant singularity is sufficient for the exact tail asymptotic behaviour for the marginal distributions and also for joint probabilities along a coordinate direction. We provide all details, not only for a "typical" case, the case with a single dominant singularity for an unknown generating function, but also for all non-typical cases which have not been studied before. A total of four types of exact tail asymptotics are found for the typical case, which have been reported in the literature. We also show that on the circle of convergence, an unknown generating function could have two dominant singularities instead of one, which can lead to a new periodic phenomena. Examples are illustrated by using this kernel method. This paper can be considered as a systematic summary and extension of existing ideas, which also contains new and interesting research results.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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