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arXiv 1010.0969math.PR
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广义随机指数的鞅性

Martingale property of generalized stochastic exponentials

Aleksandar Mijatović, Nika Novak, Mikhail Urusov

摘要:

对于满足一定可积性条件的实Borel可测函数b,可以定义过程b(Y)关于布朗运动W的随机积分,其中Y是由W驱动的扩散。众所周知,该随机积分的随机指数是一个局部鞅。在本文中,我们考虑的情况下,任意Borel可测函数b,它可能不可能直接定义的随机积分的b(Y)。然而,随机指数的概念可以推广。本文定义了一个非负过程Z,称为广义随机指数过程,它不一定是局部鞅。主要结果给出了Z是局部真鞅或一致可积鞅的确定性充要条件。

英文摘要:

For a real Borel measurable function b, which satisfies certain integrability conditions, it is possible to define a stochastic integral of the process b(Y) with respect to a Brownian motion W, where Y is a diffusion driven by W. It is well know that the stochastic exponential of this stochastic integral is a local martingale. In this paper we consider the case of an arbitrary Borel measurable function b where it may not be possible to define the stochastic integral of b(Y) directly. However the notion of the stochastic exponential can be generalized. We define a non-negative process Z, called generalized stochastic exponential, which is not necessarily a local martingale. Our main result gives deterministic necessary and sufficient conditions for Z to be a local, true or uniformly integrable martingale.

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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