数学与统计学院学术报告[2020] 118号

(高水平大学建设系列报告471号)

报告题目:  Bayesian Revisit of the Relationship between the Total Field Strength and the Volume Density of Interstellar Clouds

报告人：樊晓丹教授（香港中文大学）

报告时间：2020年11月24日周二上午10:00-11:00　　　　　　　　　　　　　　

报告地点：腾讯会议 会议号码：601970911　 　　　　　　　　　　　　

报告内容：Zeeman effect has been the only method to directly probe the magnetic field strength in molecular clouds. The Bayesian analysis of Zeeman measurements carried out by Crutcher et al (2010) is the only reference for cloud magnetic field strength. However, their results and interpretations are highly controversial. In this letter, we reviewed their model and checked the Bayesian analysis. We also relaxed some of their overly restricted parameters as an effort to let the data speak. Surprisingly, as shown in our analysis, none of the original and modified models can give a reliable estimation of the relation between the magnetic field and the number density. The non-identifiability is resulted from the fact that the number density data comes with uncertainty. Thus one needs to be cautious when concluding from such data.

报告人简历:  樊晓丹，香港中文大学统计系教授。在哈佛大学获统计学博士学位。此前，在清华大学获自动化学士学位及模式识别与智能系统硕士学位。研究兴趣为概率模型及统计计算，尤其是计算生物学/生物信息学方面的问题。

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数学与统计学院

2020年11月23日