CONFERENCE PROCEEDINGS - The 50, 70, 80,..., ∞ Conference in Mathematics

This book contains articles based on plenary lectures and short communications of The 50, 70, 80, . . . ∞ Conference in Mathematics held in Karlstad, Sweden, from August 19 to August 23, 2024. The conference is organized in honor of Professor Lars-Erik Persson on the occasion of his 80ᵗʰ birthday. The talks focused on the recent developments in Functional and Fourier Analysis, Interpolation, Homogenization and PDEs, Inequalities, Convexity Theory and Engineering Mathematics. The main reason for this variety of topics is that Lars-Erik Persson has worked in these areas at different periods, as a professor in Lulea˚, Uppsala, Narvik, Astana, Lund, and Karlstad.

The name of the conference is very significant. Each number in the name of the con- ference has its meaning, even “three dots”, i.e., “. . .” hide something. The meaning of the number 80 is obvious. The number 50 stands for 50 years in which Lars-Erik reached the finish line in the world-famous Swedish cross-country ski competition Vasaloppet. He was awarded a prestigious medal with number 56 = the number of skiers who have succeeded in fulfilling this 90 km skiing competition in 50 years (during all of its more than 100 years history of Vasaloppet). The number 70 is related to the number of his students whose doctoral dissertations he supervised. “Three dots” hide some other numbers, such as, for example: the number of published works and citations of the same papers. According to the MathSciNet database, he published more than 320 mathematical works, 10 among them books, which were cited more than 10800 times according to Google Scholar. Finally, the symbol ∞ stands here as a symbol of his famous home called the “Hotel Infinity” where many friends, international colleagues, and doctoral students enjoyed discussing and doing mathematics for many years.

Sixty-four participants from 22 countries attended the conference. Most of them sent their contributions for this proceedings and all papers were subjected to the usual review process. Many of the articles contain new, previously unpublished material, while some articles are overviews. In this collection, they are arranged alphabetically according to the last name of the first author.