Po-Han's math and non-math thoughts

Vita (中文版由此去)

Hi, I am Po-Han Hsu (許柏翰).

Currently, I am an Assistant Professor in the Department of Applied Mathematics at the National Sun Yat-Sen University (NSYSU, 國立中山大學). Prior to NSYSU, I was a Visiting Assistant Professor in the Department of Mathematical Science at the University of Cincinnati (UC).

I graduated from National Tsing Hua University (國立清華大學) in 2010 with my Bachelor's degree (數學系10級); in 2012, I received my Master's degree from National Central University (國立中央大學) under the supervision of Professor Ching-Hsian Cheng (鄭經斅). Later, I served in the Royal Solute Company in the Army of Republic of China, Taiwan (中華民國陸軍禮砲連) for a year. After my military service, I joined Academia Sinica (中研院) as a research trainee in 2013.

Then I went to Louisiana State University (LSU) to pursue my PhD degree in 2015. I learned Aye-Kuo stochastic integration from Professor Hui-Hsiung Kuo (郭輝雄) and stochastic partial differential equations from Professor P. Sundar. Finally, in May 2021, I received my PhD degree from LSU under the supervision of Professor P. Sundar.

Here is my CV.

Contact Information

Office: SC4012

Postal address: Department of Applied Mathematics, No. 70, Lienhai Rd., Kaohsiung 80424, Taiwan, R.O.C

Email address: phsu2 AT math.nsysu.edu.tw

Research Interests

I work on probabilistic number theory and stochastic partial differential equations (SPDEs).

In probabilistic number theory, I mainly focus on establishing limiting distribution of certain number-theoretic functions, e.g., prime divisor counting function, the Riemann zeta function, Dirichlet L-functions, etc. Also, I am interested in "importing" number theory techniques into theory of probability.

In SPDEs, in addition to the well-posedness of equations, I am also interested the probabilistic properties of solutions, e.g., does the solution admit a stationary distribution? How fast does the system converge to its stationary distribution? Does the system admit a large deviation estimate?

Aside from mathematics, I am fond of philosophy of science, especially HPS, the sociology of scientific knowledge (SSK), and the history of madness.

I have collaborated with Hao-Lun Fu (傅皓倫), James T. Townsend, and Cheng-Ta Yang (楊政達) in a project regarding face cognition, which directly relates to the study of artificial intelligence.

Publications

Log-correlation for shifted Dirichlet 𝐿-functions and Dedekind zeta functions of quadratic fields (with Peng-Jei Wong). Forum Math., 2025. [FM]

Three-dimensional stochastic Navier-Stokes equations with Markov switching (with P. Sundar). Stoch. Dyn. 23 (2023), no.7, Paper No. 2350057, 41 pp. [arXiv] [SD]

Ergodicity for three-dimensional stochastic Navier-Stokes equations with Markovian switching (with P. Sundar). Stoch. Anal. Appl.42 (2024), no.1, 264–287. [arXiv] [SAA]

On Selberg's central limit theorem for Dirichlet L-functions (with Peng-Jie Wong). Journal de Théorie des Nombres de Bordeaux 32 (2020), 685-710. [PDF] [JTNB]

Exponential inequalities for exit times for stochastic Navier-Stokes equations and a class of evolutions (with P. Sundar). Communications on Stochastic Analysis 12 (2018), 343-358. [PDF ] [COSA]

Preprints

On the Varying Density of Faces in Face Space: Explanation of the Atypicality Effect in Terms of a Riemannian Metric and Potential Application to the Other Race Effect (with Cheng-Ta Yang , Hao-Lun Fu , Cheng-Ju Hsieh , and James T. Townsend), submitted, [preprint].

Teaching

I have teaching experiences as an instructor at both LSU and UC. I am comfortable with both large (around 200) and small classes. Also, I am fine with teaching in virtual environment. Depending on the course content, I can switch my approach from traditional to flipped (classroom).

I have received certificate of teaching excellence. I also have received nice teaching evaluations such as 3.89/4, 4.93/5, and 6.905/7.

National Sun Yat-Sen University

Fall 2025, Math201A, Advanced Calculus (EMI)

Fall 2025, Math 302, Complex Analysis

Fall 2025, Math 676, Seminar in Stochastic Differential Equations I

Spring 2025, Math202, Advanced Calculus II

Spring 2025, Math 307, Probability Theory II (EMI)