Intro  German mathematician  
Countries  Germany  
Occupations  Mathematician Topologist University teacher  
Gender  male  
Birth  16 April 1898 (Tartu)  
Death  23 August 1973 (Tübingen)  
Star sign  Aries  
Politics  Nazi Party  
Family 


Education  University of Göttingen 
Hellmuth Kneser (16 April 1898 – 23 August 1973) was a Baltic German mathematician, who made notable contributions to group theory and topology. His most famous result may be his theorem on the existence of a prime decomposition for 3manifolds. His proof originated the concept of normal surface, a fundamental cornerstone of the theory of 3manifolds.
He was born in Dorpat, Russian Empire (now Tartu, Estonia) and died in Tübingen, Germany. He was the son of the mathematician Adolf Kneser and the father of the mathematician Martin Kneser. He assisted Wilhelm Süss in the founding of the Mathematical Research Institute of Oberwolfach and served as the director of the institute from 1958 to 1959.
Kneser had formulated the problem of noninteger iteration of functions and proved the existence of the entire Abel function of the exponential; on the base of this Abel function, he constructed the functional square root of the exponential function as a halfiteration of the exponential, i.e. a function φ such that φ(φ(z)) = exp(z).
Kneser was a student of David Hilbert. He was an advisor of a number of notable mathematicians, including Reinhold Baer.
Hellmuth Kneser was a member of the NSDAP and also the SA. In July 1934 he wrote to Ludwig Bieberbach a short note supporting his antisemitic views and stating: "May God grant German science a unitary, powerful and continued political position."