On March 15, the 2024 "Master Lecture Hall" series lecture hosted by the School of Mathematical Sciences of Jiangsu University began as scheduled in Conference Room 206 of the School of Mathematics and Science. The guest speaker of this session is Prof. Guo Kunyu of Fudan University, a famous research expert in the field of operator theory. More than 40 teachers and students from Jiangsu University, including Prof. Zhang Zhitao and Professor Wang Jun, attended the lecture. The report was presided over by Prof. Zhang Zhitao.

      Professor Guo Kunyu made a wonderful academic report on The topic of "The Beurling--Wintner problem and analytic number theory". The long-term problem of the completeness of function systems generated by odd periodic extensions of functions in L²(0,1) is discussed in detail. This question was raised by Beurling and Wintner in the 1940s and is closely related to the Riemann hypothesis. Professor Guo has used the methods of analytic number theory to complete the solution of step functions, and has proposed some in-depth applications, including the complete solution to the Kolzov completeness problem of rational functions. Professor Guo used vivid language to introduce the background of Beurling-Wintner problem and the current research progress, reflecting his deep mathematical skills. His report was rich in information, clear in order and rigorous in argumentation, which aroused great interest and attention of teachers and students present.

      After the presentation, Professor Guo gave a patient and detailed answer to everyone's questions. President Zhang Zhitao made a concluding speech to the lecture.