发表机构
University of Ottawa; University of California San Diego; University of Michigan(渥太华大学; 加州大学圣迭戈分校; 密歇根大学)
机构由 AI 辅助整理,请以论文原文为准。AI 中文总结
我们提出非交换$L^p$随机积分新框架,定义可预测线性过程,建立积分算子判据,应用于$L^p$中SDE,证明极大解存在唯一性及爆破性,推广自由和$q$-布朗运动SDE结果。
AI 中文摘要
我们提出了一个受 Bichteler 的 $L^p$-积分算子概念启发的非交换随机积分新框架,该框架极大地推广了我们先前关于针对 $L^2$-可分解过程的 $L^2$-值随机积分的理论。我们框架的核心是一种可预测线性过程,它是可预测被积函数的非交换类比。我们发展了针对“非交换 $L^p$-积分算子”的随机积分的基本性质,并建立了一个有用的判据,用以判定非交换随机过程是否为非交换 $L^p$-积分算子。该判据尤其适用于一类我们称之为可测分解过程的丰富过程类,其中包括自由布朗运动,更一般地,还包括 $q$-布朗运动。我们还证明,在适当特化时,我们的框架恢复了经典 $L^p$-积分算子的概念,但非交换理论仅关注经典随机过程的修正类。作为应用,我们利用我们的理论研究 $L^p$ 中的非交换随机微分方程(SDE)。在自然的局部 Lipschitz 和有界性假设下,我们建立了极大解的存在唯一性,并证明了具有有限寿命的极大解必须在 $L^p$ 范数下爆破。作为推论,我们获得了自由 SDE 和由 $q$-布朗运动驱动的 SDE 的新的存在唯一性结果。值得注意的是,在自由情形下,我们的结果适用于通过连续泛函演算从仅局部 Lipschitz 标量函数(而非局部算子-Lipschitz 函数)导出的系数。
英文摘要
We propose a new framework for noncommutative stochastic integration in $L^p$, inspired by Bichteler's notion of $L^p$-integrators, that massively generalizes our previous theory of $L^2$-valued stochastic integration against $L^2$-decomposable processes. Central to our framework is a noncommutative analog of a predictable integrand we call a predictable linear process. We develop basic properties of stochastic integrals against "noncommutative $L^p$-integrators" and establish a useful criterion for a noncommutative stochastic process to be a noncommutative $L^p$-integrator. This criterion applies, in particular, to a rich class of processes we call measured decomposable processes, which includes free Brownian motion and, more generally, the $q$-Brownian motions. We also show that, when specialized appropriately, our framework recovers the classical notion of an $L^p$-integrator up to the fact that the noncommutative theory sees only the modification class of a classical stochastic process. As an application, we use our theory to study noncommutative stochastic differential equations (SDEs) in $L^p$. Under natural local-Lipschitz and boundedness assumptions, we establish the existence and uniqueness of maximal solutions and show that a maximal solution with finite lifetime must blow up in $L^p$ norm. As corollaries, we obtain new existence and uniqueness results for free SDEs and SDEs driven by $q$-Brownian motion. Notably, in the free case, our results apply to coefficients arising through the continuous functional calculus from merely locally Lipschitz scalar functions, as opposed to locally operator-Lipschitz functions.
Comments66 pages, 1 figure