Käte Fenchel née Käte Sperling (21 December 1905 – 19 December 1983) was a German-born

Jew Jews (, , ), or the Jewish people, are an ethnoreligious group and nation, originating from the Israelites of ancient Israel and Judah. They also traditionally adhere to Judaism. Jewish ethnicity, religion, and community are highly inte ...

ish

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 ...

, best known for her work on

non-abelian group In mathematics, and specifically in group theory, a non-abelian group, sometimes called a non-commutative group, is a group (''G'', ∗) in which there exists at least one pair of elements ''a'' and ''b'' of ''G'', such that ''a'' ∗ ...

Life

Käte was born in

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

to a newspaper reporter and a bookkeeper, Rusza Sperling (1878–1948). As a child, she quickly learned to read and write, faster than most children. She was allowed to skip several grade levels and was awarded scholarships to attend private school. She enrolled at the

University of Berlin The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...

, but she found that she faced daunting obstacles there in the form of gender discrimination because she was pursuing studies in pure mathematics. She was encouraged to write a thesis, but she never obtained the doctorate. As a result, Käte pursued an alternative career in mathematics education. After graduation, she began working at a job teaching mathematics at a German high school from 1931 to 1933 when

Adolf Hitler Adolf Hitler (20 April 1889 – 30 April 1945) was an Austrian-born German politician who was the dictator of Nazi Germany from 1933 until Death of Adolf Hitler, his suicide in 1945. Adolf Hitler's rise to power, He rose to power as the lea ...

and the

Nazis Nazism (), formally named National Socialism (NS; , ), is the far-right politics, far-right Totalitarianism, totalitarian socio-political ideology and practices associated with Adolf Hitler and the Nazi Party (NSDAP) in Germany. During H ...

rose to power in Germany. Käte lost her job because she was a Jew, as did

Werner Fenchel Moritz Werner Fenchel (; 3 May 1905 – 24 January 1988) was a German-Danish mathematician known for his contributions to geometry and to optimization theory. Fenchel established the basic results of convex analysis and nonlinear opti ...

, another German-born Jewish mathematician, who was removed from his teaching position in

Göttingen Göttingen (, ; ; ) is a college town, university city in Lower Saxony, central Germany, the Capital (political), capital of Göttingen (district), the eponymous district. The River Leine runs through it. According to the 2022 German census, t ...

. The two mathematicians arrived in

Copenhagen Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...

in November and married in December 1933. They were joined in December 1938 by Käte's mother, who was able to emigrate from Germany. In 1940, the couple's son was born. While in

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

, she helped facilitate the escape of other German Jews facing persecution. However, in 1940, the Nazi forces invaded that country so the young family, with Käte's mother, left with thousands of other refugees for

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

. After the Allied

liberation of Denmark Liberation or liberate may refer to: Film and television * ''Liberation'' (film series), a 1970–1971 series about the Great Patriotic War * "Liberation" (''The Flash''), a TV episode * "Liberation" (''K-9''), an episode Gaming * '' Liberati ...

, the Fenchels returned to

, where Käte worked as a part-time lecturer job at

Aarhus University Aarhus University (, abbreviated AU) is a public research university. Its main campus is located in Aarhus, Denmark. It is the second largest and second oldest university in Denmark. The university is part of the Coimbra Group, the Guild, and Ut ...

in Denmark, from 1965-1970. Fenchel died on 19 December 1983.

Selected works

Fenchel authored several academic papers, and published the last of them at the age of 73. * Fenchel, Käte. "On a theorem of Frobenius." ''Mathematica Scandinavica'' 42.2 (1978): 243-250. * Fenchel, Käte. "A note about groups of odd order." ''Mathematica Scandinavica'' 10 (1962): 182-188. * Fenchel, Käte. "Relationships between the structure of a finite group and a special representation." ''Monthly'' notebooks ''for mathematics'' 66.5 (1962): 397-409. * Fenchel, Käte. "Moderne Algebra, Erster Teil, 2. Auflage.(Die Grundlehren der mathematischen Wissenschaften in Einzeldarstellungen, Band XXXIII)." (1938): 48-50. * Fenchel, Käte. "L'algèbre abstraite. (Actualités scientifiques et industrielles, 362 (Abstract algebra)." (1938): 55-55. * Fenchel, Käte. "Gruppen von linearen Transformationen.(Ergebnisse der Mathematik und ihrer Grenzgebiete, Bd. 4, Heft 2)." (Groups of Linear Transformations. (Results of Mathematics and its Borderlands, Vol. 4, Issue 2)). (1935): 116-117.

References

Bibliography

# E. Høyrup ``Käte Fenchel" in ''Women of Mathematics: A Bibliographic Sourcebook''. L. Grinstein, P. Campbell, eds New York: Greenwood Press (1987): 30–32

External links

"Kate Fenchel", Biographies of Women Mathematicians

Agnes Scott College Agnes Scott College is a Private university, private Women's Colleges in the Southern United States, women's Liberal arts colleges in the United States, liberal arts college in Decatur, Georgia. The college enrolls approximately 1,000 undergra ...

{{DEFAULTSORT:Fenchel, Kate 1905 births 1983 deaths Group theorists Mathematicians from Berlin Humboldt University of Berlin alumni 20th-century German mathematicians Jewish emigrants from Nazi Germany to Sweden Place of death missing 20th-century German women mathematicians