Hi! My name is Joy Yanjia Bai (白延佳). I am a Ph.D. student in mathematics at the University of Bonn, working in the Probability Theory group. My supervisors are Prof. Anton Bovier and Prof. Lisa Hartung.

I am interested in correlated stochastic processes and their extremal particles. Currently, I focus on the variable-speed branching Brownian motion and the statistics of its extremal particles. This is a continuation of my master’s thesis.



Ph.D. in Mathematics, 10.2019 - present, University of Bonn

M.Sc. in Mathematics, 09.2017 - 05.2019, Courant Institute, New York University

Bachelor of Economics (minor in Mathematics), 09.2013 - 05.2017, University of Hong Kong

Visiting Undergraduate Student, 01.2016 - 12.2016, Harvard University



Institut für Angewandte Mathematik

Rheinische Friedrich-Wilhelms-Universität Bonn

Endenicher Allee 60, 53115 Bonn

Office: 3.039

Email: bai (at)

Tel.: +49-228-73-62394