Adolf Kneser (19 March 1862 – 24 January 1930) was a
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems.
Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...
.
He was born in
Grüssow,
Mecklenburg
Mecklenburg (; nds, label=Low German, Mękel(n)borg ) is a historical region in northern Germany comprising the western and larger part of the federal-state Mecklenburg-Western Pomerania. The largest cities of the region are Rostock, Schwer ...
,
Germany
Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...
and died in Breslau, Germany (now
Wrocław
Wrocław (; , . german: Breslau, , also known by other names) is a city in southwestern Poland and the largest city in the historical region of Silesia. It lies on the banks of the Oder in the Silesian Lowlands of Central Europe, roughly ...
,
Poland
Poland, officially the Republic of Poland, , is a country in Central Europe. Poland is divided into Voivodeships of Poland, sixteen voivodeships and is the fifth most populous member state of the European Union (EU), with over 38 mill ...
).
He is the father of the mathematician
Hellmuth Kneser
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-mani ...
and the grandfather of the mathematician
Martin Kneser
Martin Kneser (21 January 1928 – 16 February 2004) was a German mathematician. His father Hellmuth Kneser and grandfather Adolf Kneser were also mathematicians.
He obtained his PhD in 1950 from Humboldt University of Berlin with the disse ...
.
Kneser is known for the first proof of the
four-vertex theorem that applied in general to non-convex curves.
Kneser's theorem on differential equations is named after him, and provides criteria to decide whether a
differential equation
In mathematics, a differential equation is an equation that relates one or more unknown functions and their derivatives. In applications, the functions generally represent physical quantities, the derivatives represent their rates of change, a ...
is
oscillating
Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum ...
. He is also one of the namesakes of the
Tait–Kneser theorem
In differential geometry, the Tait–Kneser theorem states that, if a smooth plane curve has monotonic curvature, then the osculating circles of the curve are disjoint and nested within each other.
The logarithmic spiral or the pictured Archime ...
on
osculating circle
In differential geometry of curves, the osculating circle of a sufficiently smooth plane curve at a given point ''p'' on the curve has been traditionally defined as the circle passing through ''p'' and a pair of additional points on the curve ...
s.
Selected publications
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References
External links
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1862 births
1930 deaths
19th-century German mathematicians
20th-century German mathematicians
University of Tartu faculty
{{Germany-mathematician-stub