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arXiv 0905.3701math.PRq-fin.GN
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一类局部鞅的鞅性

On the Martingale Property of Certain Local Martingales

Aleksandar Mijatovic, Mikhail Urusov

摘要:

连续局部鞅$M$的随机指数$Z_t=\exp\{M_t-M_0-(1/2) <M,M>_t\}$本身也是连续局部鞅.在过程$M_t=\int_0^t b(Y_u)\,dW_u$和过程$Y$是由布朗运动$W$驱动的一维扩散过程的情况下,给出了过程$Z$是真鞅的一个充要条件.此外,我们还给出了$Z$在相同的条件下是一致可积鞅的一个充要条件。这些条件是确定性的,并且仅用函数$b$和$Y$的漂移和扩散系数来表示。作为一个应用程序,我们提供了一个确定性的标准,在一维设置中的气泡。

英文摘要:

The stochastic exponential $Z_t=\exp\{M_t-M_0-(1/2) <M,M>_t\}$ of a continuous local martingale $M$ is itself a continuous local martingale. We give a necessary and sufficient condition for the process $Z$ to be a true martingale in the case where $M_t=\int_0^t b(Y_u)\,dW_u$ and $Y$ is a one-dimensional diffusion driven by a Brownian motion $W$. Furthermore, we provide a necessary and sufficient condition for $Z$ to be a uniformly integrable martingale in the same setting. These conditions are deterministic and expressed only in terms of the function $b$ and the drift and diffusion coefficients of $Y$. As an application we provide a deterministic criterion for the absence of bubbles in a one-dimensional setting.

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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