He decided as a result of that meeting to move towards algebraic number theory and an Alexander von Humboldt Foundation Fellowship allowed him to spend the years from 1957 to 1959 as a research fellow at the Mathematisches Seminar of Hamburg University, working with Hasse 's research group.
Siya nagpasya bilang isang resulta ng na pagkikita upang ilipat sa algebraic numero ng teorya at ng isang Alexander von Humboldt Foundation Fellowship pinahihintulutan sa kanya na gumastos ng taong 1957-1959 bilang isang pananaliksik kapwa sa Mathematisches pantas-aral ng Hamburg University, nagtatrabaho sa Hasse 's research group .