Konrad Knopp

Konrad Hermann Theodor Knopp (22 July 1882, Berlin, Germany – 20 April 1957, Annecy, France) was a German mathematician who worked on generalized limits and complex functions.

Family and education

Knopp was born in 1882 in Berlin to Paul Knopp (1845-1904), a businessman in manufacturing, and Helene (1857-1923), neé Ostertun, whose own father was a forester. Paul's hometown of Neustettin, then part of Germany, became Polish territory after the Second World War and is now called Szczecinek. Konrad himself married in 1910, to the painter Gertrud Kressner (1879-1974), and had a son and a daughter.

Konrad was primarily educated in Berlin, with a brief sojourn at the University of Lausanne in 1901 for a single semester, before settling at the University of Berlin, where he remained for his doctoral studies. His doctoral thesis, entitled "Grenzwerte von Reihen bei der Annäherung an die Konvergenzgrenze", was supervised by Schottky and Frobenius; he received his PhD in 1907.

Travels, teaching, and military career

Knopp traveled widely in Asia, taking teaching jobs in Nagasaki, Japan (1908-9), at the Handelshochschule, and in Qingdao, China (1910-11), at the German-Chinese academy there, and spending some time in India and China following his stay in Japan. His wedding to Kressner, the daughter of Colonel Karl Kressner and Hedwig Rebling, took place in Germany between these periods. After Qingdao he returned to Germany for good and taught at military academies while writing his habilitation thesis for Berlin University.

During the first World War he was an officer and was wounded at the beginning of the war, which resulted in his discharge from the army; by the autumn of 1914 he was teaching at Berlin University. In the following year he was appointed as an extraordinary professor at the University of Königsberg, becoming an ordinary professor there in 1919. In 1926 he accepted a professorship at Tübingen University as the chair of mathematics, and remained there until his retirement in 1950.

Publications and editions

Articles

Selected articles of Knopp include:
* cite journal
last = Knopp
first = Konrad
title = Bemerkungen zur Struktur einer linearen perfekten nirgends dichten Punktmenge
journal = Math. Ann.
volume = 77
issue = 3
year = 1916
pages = 438–451
url = http://dz-srv1.sub.uni-goettingen.de/sub/digbib/loader?ht=VIEW&did=D37503
doi = 10.1007/BF01475872 (in German)
* cite journal
last = Knopp
first = Konrad
title = Ein einfaches Verfahren zur Bildüng stetiger nirgends differenzierbarer Funktionen
journal = Math. Z.
year = 1918
volume = 2
issue = 1-2
pages = 1–26
url = http://dz-srv1.sub.uni-goettingen.de/sub/digbib/loader?ht=VIEW&did=D17426
doi = 10.1007/BF01212897 (in German)
* cite journal
last = Knopp
first = Konrad
title = Mittelwertbildung und Reihentransformation
journal = Math. Z.
year = 1920
volume = 6
issue = 1-2
pages = 118–123
url = http://dz-srv1.sub.uni-goettingen.de/sub/digbib/loader?ht=VIEW&did=D16815
doi = 10.1007/BF01202996 (in German)
* cite journal
last = Knopp
first = Konrad
title = Über das Eulersche Summierungsverfahren
journal = Math. Z.
year = 1923
volume = 18
issue = 1
pages = 125=156
url = http://dz-srv1.sub.uni-goettingen.de/sub/digbib/loader?ht=VIEW&did=D8501
doi = 10.1007/BF01192401 (in German)
* cite journal
last = Knopp
first = Konrad
title = Zur Theorie der Limitierungsverfahren
journal = Math. Z.
year = 1930
volume = 31
issue = 1
pages = 97–172, 276–305
url = http://dz-srv1.sub.uni-goettingen.de/sub/digbib/loader?ht=VIEW&did=D85239
doi = 10.1007/BF01246399 (in German)
* cite journal
last = Knopp
first = Konrad
title = Über die maximalen Abstände und Verhältnisse verschiedener Mittelwerte
journal = Math. Z.
year = 1935
volume = 39
issue = 1
pages = 768–776
url = http://dz-srv1.sub.uni-goettingen.de/sub/digbib/loader?ht=VIEW&did=D17222
doi = 10.1007/BF01201392 (in German)

He was the co-founder of Mathematische Zeitschrift (in which the majority of his above-cited articles are published) in 1918, being the editor from 1934 to 1952.

After retirement Knopp continued to do mathematics, publishing for example
* cite journal
last = Knopp
first = Konrad
title = Zwei Abelsche Sätze
journal = Acad. Serbe Sci. Publ. Inst. Math.
volume = 4
pages = 89–94
year = 1952and delivering the lecture "Folgenräume und Limitierungsverfahren" at the first meeting of the International Mathematics Union in 1952.

Books

Knopp's mathematical research was on "generalized limits" and he wrote two books on sequences and series:
* cite book
last = Knopp
first = Konrad
title = Infinite Sequences and Series
isbn = 978-0486601533
publisher = Dover Publications
date = 1956
language = English translation
* cite book
last = Knopp
first = Konrad
title = Theory and Application of Infinite Series
publisher = Dover Publications
date = 1990
isbn = 978-0486661650
language = English translation

He also authored two texts on functions of a complex variable as well as a problem book:
* cite book
last = Knopp
first = Konrad
title = Theory of Functions
isbn = 978-0486692197
publisher = Dover Publications
date = 1996
language = English translation
* cite book
last = Knopp
first = Konrad
title = Elements of the Theory of Functions
isbn = 978-0486601540
publisher = Dover Publications
date = 1952
language = English translation
* cite book
last = Knopp
first = Konrad
title = Problem Book in the Theory of Functions
publisher = Dover Publications
isbn = 978-0486414515
date = 2000
language = English translation

He also produced the sixth edition of the three-volume work (a fourth volume was later added by Friedrich Lösch in 1980):
* cite book
last = von Mangoldt
first = Hans
others = ed. Konrad Knopp (6th ed.)
title = Höhere Mathematik: eine Einführung für Studierende und zum Selbststudium
publisher = S. Hirzel Verlag
location = Stuttgart
year = 1990
edition = 17th edition
isbn = 978-3-7776-0463-3

References

The following works were used as sources for the MacTutor biography on which this article was originally based:
* cite book
last = Freudenthal
first = Hans
authorlink = Hans Freudenthal
title = Dictionary of Scientific Biography
chapter = Biography of Konrad Knopp
location = New York
year = 1970-1990
* cite journal
author = Anonymous
title = Obituary: Konrad Knopp
journal = Math. Z.
year = 1957
volume = 67
issue = 1
pages = v
* cite journal
last = Kamke
first = E.
coauthors = K. Zeller
title = Konrad Knopp
journal = Jahresberichte der Deutschen Mathematikervereinigung
volume = 60
year = 1958
pages = 44–49
* cite journal
last = Kamke
first = E.
coauthors = K. Zeller
title = Obituary: Konrad Knopp
journal = Jahresberichte der Deutschen Mathematikervereinigung
year = 1957
volume = 60
pages = 43–49
* cite journal
last = Knopp
first = Konrad
title = Mathematics as a cultural activity
journal = Math. Intelligencer
volume = 7
issue = 1
year = 1985
pages = 7–14, 26
* cite journal
last = Löbell
first = F.
title = Obituary: Konrad Knopp
journal = Jbuch. Bayer. Akad. Wiss. München
year = 1958
pages = 187–189

External links

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