At 14:30 on June 7, the 2022 "Master Lecture Series" jointly sponsored by the School of Mathematical Sciences and the Institute of Applied Systems Analysis of Jiangsu University started on schedule at Cloud. The invited guest speaker is Professor Hu Xijun, a famous research expert in dynamical systems and nonlinear generalized functional analysis in China, and the executive vice dean of Shandong University School of Mathematics. More than forty teachers and students attended this lecture, including Prof. Zhang Zhitao and Prof. Wang Jun from Jiangsu University. The report was hosted by Dean Zhang Zhitao of the School of Mathematical Sciences.

Prof. Xijun Hu gave a wonderful lecture on "Index theory and stability of elliptic relative equilibria in Planar n-body problem". First, he gave a brief introduction to the concept of n-body problem and planar central configuration at , and gave the background of Elliptic relative equilibria special solutions, such as Lagrangian equilateral triangle, Lagrangian point, Euler commutative problem, 1+n problem, etc. Further, he introduced the stability and approximation problem, and gave the important basis to judge the stability -Maslov indicator, and introduces Maslov indicator estimation method-Trace formula method, and finally introduces their research results related to Eulerian orbit stability analysis.

Professor Hu used vivid language to introduce the celestial problems in astronomy and their deep connection with dynamical systems, reflecting his profound mathematical skills. His informative, well-organized and rigorously argued presentation attracted great interest and attention of the students and faculty present.

After the presentation, Professor Hu gave patient and detailed answers to the questions of concern. President Zhang Zhitao made a concluding speech on the lecture.