Ernst Witt (26 June 1911 – 3 July 1991) was a German mathematician, one of the leading algebraists of his time.[1]
Witt was born on the island of Alsen, then a part of the German Empire. Shortly after his birth, his parents moved the family to China to work as missionaries,[2] and he did not return to Europe until he was nine.[2]
After his schooling, Witt went to the University of Freiburg and the University of Göttingen. He joined the NSDAP (Nazi Party) and was an active party member.[3] Witt was awarded a Ph.D. at the University of Göttingen in 1933 with a thesis titled: "Riemann-Roch theorem and zeta-Function in hypercomplexes"[4] (Riemann-Rochscher Satz und Zeta-Funktion im Hyperkomplexen) that was supervised by Gustav Herglotz, with Emmy Noether suggesting the topic for the doctorate.[5] He became a qualified lecturer and gave guest lectures in Göttingen and Hamburg.[5] He was also associated with the team led by Helmut Hasse who led his habilitation. In June 1936, he gave his habilitation lecture.[4]
During World War II he joined a group of five mathematicians, recruited by Wilhelm Fenner, and which included Georg Aumann, Alexander Aigner, Oswald Teichmüller, Johann Friedrich Schultze and their leader professor Wolfgang Franz, to form the backbone of the new mathematical research department in the late 1930s that would eventually be called: Section IVc of Cipher Department of the High Command of the Wehrmacht (abbr. OKW/Chi).[6][7]
From 1937 until 1979, he taught at the University of Hamburg.[8] He died in Hamburg in 1991, shortly after his 80th birthday.
Witt's work has been highly influential. His invention of the Witt vectors clarifies and generalizes the structure of the p-adic numbers.[9] It has become fundamental to p-adic Hodge theory.
ウィットは任意の体上の二次形式の理論の創始者であった。[ 10 ]彼はウィット消去定理を含むいくつかの重要な結果を証明した。彼は体上のすべての二次形式のウィット環を定義し、それは現在この理論の中心的な対象となっている。[ 11 ]
ポアンカレ・バーコフ・ウィットの定理は、リー代数の研究において基礎となる定理である。代数幾何学において、有限体上の代数曲線のハッセ・ウィット行列は、標数pの曲線の次数pの巡回エタール被覆を決定する。
1970年代、ウィットは1940年に、後に「リーチ格子」と呼ばれることになるものを、ジョン・リーチが1965年に発見する何年も前に発見したと主張したが、ウィットはその発見を公表しておらず、彼が具体的に何をしたのかは不明である。[ 12 ] [ 13 ]