Were Maxim Kontsevich and Aleksandr Lyapunov both mathematicians?
Aleksandr Lyapunov Aleksandr Mikhailovich Lyapunov (Russian: Алекса́ндр Миха́йлович Ляпуно́в , ] ; June 6 [O.S. May 25] 1857 – November 3, 1918) was a Russian mathematician, mechanician and physicist. His surname is sometimes romanized as Ljapunov, Liapunov, Liapounoff or Ljapunow. He was the son of astronomer Mikhail Lyapunov and the brother of pianist and composer Sergei Lyapunov.
Yuri Kondratyuk Yuriy Vasilievich Kondratyuk (real name Aleksandr Ignatyevich Shargei, Ukrainian: Олександр Гнатович Шаргей , "Oleksandr Hnatovych Sharhei") (June 21, 1897 – February 1942) was a Soviet engineer and mathematician. He was a pioneer of astronautics and spaceflight, a theoretician and a visionary who, in the early 20th century, developed the first known lunar orbit rendezvous (LOR), a key concept for landing and return spaceflight from Earth to the Moon. The LOR was later used for the plotting of the first actual human spaceflight to the Moon. Many other aspects of spaceflight and space exploration are covered in his works.