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 3-manifolds. His proof originated the concept of
normal surface, a fundamental cornerstone of the theory of
3-manifold
In mathematics, a 3-manifold is a space that locally looks like Euclidean 3-dimensional space. A 3-manifold can be thought of as a possible shape of the universe. Just as a sphere looks like a plane to a small enough observer, all 3-manifolds lo ...
s.
He was born in
Dorpat,
Russian Empire (now
Tartu
Tartu is the second largest city in Estonia after the Northern European country's political and financial capital, Tallinn. Tartu has a population of 91,407 (as of 2021). It is southeast of Tallinn and 245 kilometres (152 miles) northeast of ...
,
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
The Oberwolfach Research Institute for Mathematics (german: Mathematisches Forschungsinstitut Oberwolfach) is a center for mathematical research in Oberwolfach, Germany. It was founded by mathematician Wilhelm Süss in 1944.
It organizes weekl ...
and served as the director of the institute from 1958 to 1959.
He was an editor of
Mathematische Zeitschrift,
Archiv der Mathematik and
Aequationes Mathematicae.
Kneser formulated the problem of non-integer 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 half-iteration of the exponential, i.e. a function such that .
[
]
Kneser was a student of
David Hilbert
David Hilbert (; ; 23 January 1862 – 14 February 1943) was a German mathematician, one of the most influential mathematicians of the 19th and early 20th centuries. Hilbert discovered and developed a broad range of fundamental ideas in many a ...
. 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 anti-semitic views and stating: "May God grant German science a unitary, powerful and continued political position."
[Sanford L. Segal]
Mathematicians under the Nazis
Princeton University Press, 2003, page 276
Selected publications
* ''Funktionentheorie.'' Studia Mathematica, Göttingen, 1958;
2nd edition 1966.
*Gerhard Betsch, Karl H. Hofmann (eds.): ''Gesammelte Abhandlungen'', De Gruyter 2005
References
External links
*
*
{{DEFAULTSORT:Kneser, Hellmuth
1898 births
1973 deaths
People from Tartu
People from Kreis Dorpat
Baltic-German people
Nazi Party members
20th-century German mathematicians
Group theorists
Topologists
Academic staff of the University of Greifswald
Sturmabteilung personnel
Emigrants from the Russian Empire to Germany