This book is a collection of original, peer-reviewed papers presented by the speakers at the MSJ–KMS Joint Meeting 2023, held at the Sendai International Center on September 19, 2023. The papers reflect the themes and discussions that took place during the meeting. The MSJ–KMS/KMS–MSJ Joint Meeting is a series of collaborative conferences organized by the Mathematical Society of Japan (MSJ) and the Korean Mathematical Society (KMS). This series began on September 17, 2012, at Kyushu University (Centennial Hall, Medical School), and has continued to foster academic exchange between the two societies. Notable past meetings include the KMS–MSJ Joint Meeting 2016 at Seoul National University, held in celebration of the 70th anniversary of the KMS, and the MSJ–KMS Joint Meeting 2021, which was conducted online.

The 2023 meeting consisted of two parts: a morning session featuring plenary lectures and an afternoon session divided into four parallel sessions—algebra, geometry and topology, analysis, and probability theory and applied mathematics. Speakers were nominated by the two societies in recognition of their active contributions to these fields.

This book is intended for a wide audience of pure and applied mathematicians, including researchers and graduate students interested in current developments across various areas of mathematics. It offers valuable insights into recent research trends and fosters deeper understanding through the diverse perspectives presented by the invited speakers.

Tomohide Terasoma is a full professor of Hosei University. He was an invited speaker of International Congress of Mathematicians in 2006 and served as the president of the Mathematical Society of Japan between 2019 and 2021.

JongHae Keum Born is a distinguished professor of KIAS. He was an invited speaker of International Congress of Mathematicians in 2018. He served as the president of Korean Mathematical Society between 2019 and 2022.