报告题目：Transition Phenomena in Stochastic Dynamical Systems

报 告 人：段金桥教授（美国伊利诺理工学院）

报告时间：2020年8月5日星期三上午10:00-11:40

报告地点：腾讯会议ID：314 936 422

报告摘要：Dynamical systems are often under random fluctuations. The noisy fluctuations may be Gaussian or non-Gaussian, which are modeled by Brownian motion or α-stable Levy motion, respectively. Non-Gaussianity of the noise manifests as nonlocality at a “macroscopic” level. Stochastic dynamical systems with non-Gaussian noise (modeled by α-stable Levy motion) have attracted a lot of attention recently. The non-Gaussianity index α is a significant indicator for various dynamical behaviors. Transition phenomena are special events of evolution from one metastable state to another in stochastic dynamical systems, caused by the interaction between nonlinearity and uncertainty. Examples for such events are phase transition, pattern change, gene transcription, climate change, abrupt change, extreme transition, and other rare events. The most probable transition pathways are the maximal likely (in the sense of optimizing a probability or an action functional) trajectory between metastable states. The speaker will present recent work on analyzing and estimating the most probable transition pathways for stochastic dynamical systems, in the context of the Onsager-Machlup action functionals.

个人简历：段金桥本科毕业于武汉大学，硕士毕业于中国科学院，博士毕业于美国康乃尔大学（Cornell University），在美国加州理工学院(California Institute of Technology)博士后研究。

现任美国伊利诺理工学院（Illinois Institute of Technology） 终身教授。曾任美国国家纯粹与应用数学所副所长（挂靠在美国加州大学洛杉矶分校，Institute for Pure and Applied Mathematics,

www.ipam.ucla.edu ）。

段金桥教授的研究领域包括非线性动力系统，随机动力系统，随机偏微分方程， 以及数学与其它学科的交叉研究。在随机动力系统，随机偏微分方程及其在数据科学，地球系统和生物系统应用研究领域作出了重要贡献。 段金桥教授曾获得欧洲地球物理学会青年科学家论文奖。 他现任Stochastics and Dynamics (“随机动力系统”) 杂志管理编辑。 他还任Interdisciplinary Mathematical Sciences (“跨学科应用数学丛书”) 主编， 以及“Nonlinear Processes in Geophysics”编委。