LUDWIG D. FADDEEV (1934-2017)

1. First steps

  Ludwig Faddeev was born in Leningrad (now St. Peteresburg), USSR (now   Russian Federation) on March 23, 1934,   to a family of mathematicians Dmitrij Konstantinovich Faddeev1 and Vera Nikolaevna Faddeeva2. From childhood Ludwig   was exposed to classical music, to   piano, in particular, he seriously considered   attending to Leningrad   conservatory an alternative to the university.  
  At the time of his graduation from high   school in 1951 his father was the Dean of the Mathematics Department at the Leningrad State University. So young Ludwig   decided to go to the Physics Department. When he was a junior, a new Chair3 of Mathematical Physics was established at the Physics Department. First graduating class in mathematical physics had five students, two young men and three young   women, among them were L. Faddeev and N.   Uraltseva.        

  At the time O.A. Ladyzhenskaya was a young energetic professor at the department and had great respect among students. She was lecturing on the theory of   functions of complex variables, operator algebras, partial differential equations and   other subjects. When Ludwig was in the   fourth year of his studies, she organized a   student seminar based on the book by K.   O. Friedrichs “Mathematical aspects of   the quantum theory of fields”[1].   Ladyzhenskaya learned about this book from her   colleagues at Courant. Faddeev was a key   participant at the seminar. The book   was translated and studied in all   detail. According to his recollections, Faddeev   was particularly impressed by the last   chapter (by the appendix) of the book, which   was focused on scattering theory. He was   using Friedrichs perturbation theory of continuum spectrum successfully many   times. It was an important tool in his study   of scattering and inverse problems. At   this time Ladyzhenskaya became his adviser.
   She also suggested to him to study the   work of N. Levinson [2] on the inverse scattering theory and to present it at the   seminar. This was a very profound moment:   the inverse scattering problems influenced   Ludwig’s research for very long time.
   Regarding these times he wrote about   O.A. Ladyzhenskaya: ”I am forever grateful  for the direction she gave me...”

D.K. Faddeev was one of the leading figures in algebra in the Soviet Union. Among his many results was the invention of group cohomology. This work was done in during evacuation from Leningrad, mostly in Kazan, during the Siege of Leningrad (Leningrad Blockade) by the German Army Group North during the World War II, when Ludwig was 7 to 9 years old. Due to this unfortunate timing this work was noticed only later, after works of Eilenberg and MacLane.