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arXiv 1011.4002cond-mat.stat-mech
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$d$维指数飞行的碰撞密度和平均停留时间

Collision densities and mean residence times for $d$-dimensional exponential flights

Andrea Zoia, Eric Dumonteil, Alain Mazzolo

摘要:

在本文中,我们分析了{ \em指数航班},随机过程,管理许多随机输运现象,如中子传播,化学/生物物种迁移,或电子运动的演变的一些方面。我们介绍了一个一般的框架$d$维设置,并强调指数航班代表一个欺骗性的简单系统,在大多数情况下,封闭形式的公式很难得到。我们推导出一些新的精确(在可能的情况下)或渐近的结果,其中的2D系统,一个长期存在的问题,在物理学中的稳态概率密度,并在一个给定的体积的平均停留时间。有界或无界,以及散射或吸收域进行检查,并进行蒙特卡罗模拟,以支持我们的研究结果。

英文摘要:

In this paper we analyze some aspects of {\em exponential flights}, a stochastic process that governs the evolution of many random transport phenomena, such as neutron propagation, chemical/biological species migration, or electron motion. We introduce a general framework for $d$-dimensional setups, and emphasize that exponential flights represent a deceivingly simple system, where in most cases closed-form formulas can hardly be obtained. We derive a number of novel exact (where possible) or asymptotic results, among which the stationary probability density for 2d systems, a long-standing issue in Physics, and the mean residence time in a given volume. Bounded or unbounded, as well as scattering or absorbing domains are examined, and Monte Carlo simulations are performed so as to support our findings.

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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