Obituary for Yuri Manin

7th January 2023 Yuri I. Manin died. Shortly before his 86th birthday he passed away.
 
He was a mathematician and visionary as hardly anybody else. He worked on different papers by the ancient master (Diophantus), Galois, Grothendieck, Gödel, Kolmogoroff, Mordell et al. and he cooperated on different fields with colleagues and students. He had a wide range of mathematical issues and influenced the entire field of modern mathematics with his widely acknowledges results.
 
Beyond that he dealt with physical problems of quantum theory and connections with mathematics and physics. By calculating of the so-called Polyakov measure on the moduli spaces of Riemann surfaces he found the similarity of his methods with these in Gerd Faltings’ final proof of the Mordell Conjecture. He writes, "that even most abstruse mathematical ideas are somehow predestined to be in harmony with the physical world…"

When he was in Moscow in the 1960s and 80s, his most creative time, influenced by linguists and philologists, he began working on "human studies, role of human culture, history, and psychology" and took great delight in it. He was surprised about the terminological precision, cultural symbols and the change of meaning of words as e.g.  "evolution", "relativity", "the subconscious" or on such words although not yet symbols, have passed beyond being merely terms: "set", "symmetry", "space-time". It’s not only single words but the language as whole and the very beginning of language too are issues of his personal interest and dedication. In those he found mathematical structures (semantic spaces) and widely published about them.

To him mathematics were not only a "great and important craft" but more than that "a metaphor of human existence".

Marietta Ehret, 26.02.2023
Translation by Martin Franke and M.E.