Quickest Real-Time Detection of Multiple Brownian Drifts

التفاصيل البيبلوغرافية
العنوان: Quickest Real-Time Detection of Multiple Brownian Drifts
المؤلفون: Ernst, Philip A., Mei, Hongwei, Peskir, Goran
سنة النشر: 2023
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Probability, 60G40, 60J65, 60H30
الوصف: Consider the motion of a Brownian particle in $n$ dimensions, whose coordinate processes are standard Brownian motions with zero drift initially, and then at some random/unobservable time, exactly $k$ of the coordinate processes get a (known) non-zero drift permanently. Given that the position of the Brownian particle is being observed in real time, the problem is to detect the time at which the $k$ coordinate processes get the drift as accurately as possible. We solve this problem in the most uncertain scenario when the random/unobservable time is (i) exponentially distributed and (ii) independent from the initial motion without drift. The solution is expressed in terms of a stopping time that minimises the probability of a false early detection and the expected delay of a missed late detection. The elliptic case $k=1$ has been settled in Ernst and Peskir (2022) where the hypoelliptic case $1 < k < n$ resolved in the present paper was left open (the case $k = n$ reduces to the classic case $n=1$ having a known solution). We also show that the methodology developed solves the problem in the general case where exactly $k$ is relaxed to any number of the coordinate processes getting the drift. To our knowledge this is the first time that such a multi-dimensional hypoelliptic problem has been solved exactly in the literature.
Comment: 26 pages, 1 figure. arXiv admin note: substantial text overlap with arXiv:2007.14786
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2305.05721
رقم الانضمام: edsarx.2305.05721
قاعدة البيانات: arXiv