应数学与统计学院邓伟华教授和许鹏博博士的联合邀请，德国波茨坦大学物理与天文研究所教授Ralf Metzler将于近期进行线上学术报告。

报告题目：DON'T AVERAGE! --- LEARNING FROM FLUCTUATIONS IN DIFFUSIVE PROCESSES

时    间：2020年12月10日16:30

地    点：理工楼 518

线上报告ID：827 196 794（腾讯会议，密码：202012）

报告摘要：After a brief introduction to the history of Brownian motion I will address current challenges to the physical understanding of diffusive processes in complex systems. These challenges arise from modern experimental techniques such as single particle tracking as well as supercomputing studies. Typically, these approaches provide relatively few trajectories of tracer particles, of finite measurement time. Evaluating individual trajectories, for instance, in terms of time-averaged mean squared displacements, the results will naturally fluctuate from one trajectory to another. Instead of averaging further over all measured trajectories, I will argue that one can extract valuable information from these fluctuations, helping us to decipher the physical mechanisms behind the observed particle motion, including measurement noise. For both normal and anomalous diffusion the exact form of these fluctuations will be discussed for measured moments as well as the single-trajectory power spectrum. Moreover, the emergence of non-Gaussian forms of the displacement distribution due to inhomogeneous environments will be addressed. In a similar spirit I will argue that cognisance of the entire distribution of reaction times is vital for the understanding of low-concentration chemical reactions, rather than focusing on mean reaction rates. Finally, current data science approaches to the analysis of diffusing data are introduced in terms of Bayesian and machine learning techniques.

个人简介

Ralf Metzler教授是德国波茨坦大学的终身教授，理论物理系主任，物理和天文学研究所所长,统计物理和反常统计动力学领域的国际著名专家。Metzler教授于1996年获得博士学位，1998年至2000年在特拉维夫大学任博士后研究员，2000年至2002年在麻省理工学院任博士后研究员，2006年至2007年在渥太华大学任副教授，2007年至2011年在慕尼黑大学任教授，2011年至今任波茨坦大学理论物理终身教授。他有相当丰富的科研成果，多次在Phys. Rev. Lett.，Proc. Natl. Acad. Sci. USA，Sci. Rep.，New J. Phys.等世界著名期刊上发表论文，目前发表文章250余篇，被引用次数超过16900次，H指数59。

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数学与统计学院

萃英学院

2020年12月8日