Facts: - death place: montagnola , lugano , switzerland - doctoral students: theodore motzkin walter gautschi stefan e. warschawski - influences: david hilbert erich hecke - death date: 20 november 1986 - doctoral advisor: edmund landau felix klein - academic advisors: dmitry grave kurt hensel - birth date: 25 september 1893 - name: alexander ostrowski - image: alexander ostrowski.jpg - birth place: kiev , russian empire Based on these bullet points, write a short biography describing the life of alexander ostrowski .
alexander markowich ostrowski -lrb- ; 25 september 1893 , kiev , russian empire -- 20 november 1986 , montagnola , lugano , switzerland -rrb- was a mathematician .his father mark having been a merchant , alexander ostrowski attended the kiev college of commerce , not a high school , and thus had an insufficient qualification to be admitted to university .however , his extraordinary talent did not remain undetected : ostrowski 's mentor grave wrote to landau and hensel for help .subsequently ostrowski began to study mathematics at marburg university under hensel 's supervision in 1912 .after world war i had ended ostrowski moved on to gottingen where he wrote his doctoral dissertation and was influenced by hilbert , klein and landau .in 1920 , after having obtained his doctorate , ostrowski moved to hamburg where he worked as hecke 's assistant and finished his habilitation in 1922 , becoming professor of mathematics at basel .