Ernst Kummer
Ernst Kummer  

Ernst Eduard Kummer


Born 
Sorau, Prussia 
29 January 1810
Died  14 May 1893 Berlin, Brandenburg, Germany 
(aged 83)
Residence  Germany 
Nationality  Prussian 
Alma mater  University of Halle (Ph.D., 1831) 
Known for  Bessel functions, Kummer theory, Kummer surface, and other contributions 
Scientific career  
Fields  Mathematician 
Institutions 
University of Berlin University of Breslau Gewerbeinstitut Lomonosov University 
Thesis  De cosinuum et sinuum potestatibus secundum cosinus et sinus arcuum multiplicium evolvendis (1831/1832) 
Doctoral advisor  Heinrich Scherk 
Doctoral students 
Gotthold Eisenstein Georg Frobenius Lazarus Fuchs Wilhelm Killing Adolf Kneser Franz Mertens Hermann Schwarz Georg Cantor Hans Carl Friedrich von Mangoldt Adolf Piltz 
Ernst Eduard Kummer (29 January 1810 – 14 May 1893) was a German mathematician. Skilled in applied mathematics, Kummer trained German army officers in ballistics; afterwards, he taught for 10 years in a gymnasium, the German equivalent of high school, where he inspired the mathematical career of Leopold Kronecker.
Life
Kummer was born in Sorau, Brandenburg (then part of Prussia). He was awarded a PhD from the University of Halle in 1831 for writing a prizewinning mathematical essay (De cosinuum et sinuum potestatibus secundum cosinus et sinus arcuum multiplicium evolvendis), which was eventually published a year later.
Kummer was married in 1840 to Ottilie Mendelssohn, daughter of Nathan Mendelssohn and Henriette Itzig. Ottilie was a cousin of Felix Mendelssohn and his sister Rebecca Mendelssohn Bartholdy, the wife of the mathematician Peter Gustav Lejeune Dirichlet. His second wife (whom he married soon after the death of Ottilie in 1848), Bertha Cauer, was a maternal cousin of Ottilie. Overall, he had 13 children. His daughter Marie married the mathematician Hermann Schwarz. Kummer retired from teaching and from mathematics in 1890 and died three years later in Berlin.
Mathematics
Kummer made several contributions to mathematics in different areas; he codified some of the relations between different hypergeometric series, known as contiguity relations. The Kummer surface results from taking the quotient of a twodimensional abelian variety by the cyclic group {1, −1} (an early orbifold: it has 16 singular points, and its geometry was intensively studied in the nineteenth century).
Kummer also proved Fermat's last theorem for a considerable class of prime exponents (see regular prime, ideal class group). His methods were closer, perhaps, to padic ones than to ideal theory as understood later, though the term 'ideal' arose here. He studied what were later called Kummer extensions of fields: that is, extensions generated by adjoining an nth root to a field already containing a primitive nth root of unity. This is a significant extension of the theory of quadratic extensions, and the genus theory of quadratic forms (linked to the 2torsion of the class group). As such, it is still foundational for class field theory.
Publications
 Kummer, Ernst Eduard (1975), Weil, André, ed., Collected papers. Volume 1: Contributions to Number Theory, Berlin, New York: SpringerVerlag, ISBN 9780387068350, MR 0465760^{[1]}
 Kummer, Ernst Eduard (1975), Weil, André, ed., Collected papers. Volume II: Function theory, geometry and miscellaneous, Berlin, New York: SpringerVerlag, ISBN 9783540068365, MR 0465761^{[1]}
See also
 Kummer configuration
 Kummer's congruence
 Kummer series
 Kummer theory
 Kummer's theorem, on primepower divisors of binomial coefficients
 Kummer's function
 Kummer ring
 Kummer sum
 Kummer variety
References
 ^ ^{a} ^{b} Mazur, Barry (1977). "Review: Kummer, Collected Papers". Bull. Amer. Math. Soc. 83 (5): 976–988. doi:10.1090/s000299041977143437.
 Eric Temple Bell, Men of Mathematics, Simon and Schuster, New York: 1986.
 R. W. H. T. Hudson, Kummer's Quartic Surface, Cambridge, [1905] rept. 1990.
 "Ernst Kummer," in Dictionary of Scientific Biography, ed. C. Gillispie, NY: Scribners 1970–90.
External links
 O'Connor, John J.; Robertson, Edmund F., "Ernst Kummer", MacTutor History of Mathematics archive, University of St Andrews.
 Works by or about Ernst Kummer at Internet Archive
 Biography of Ernst Kummer
 Ernst Kummer at the Mathematics Genealogy Project
 1810 births
 1893 deaths
 People from Żary
 19thcentury German mathematicians
 Number theorists
 German Lutherans
 People from the Province of Brandenburg
 Martin Luther University of HalleWittenberg alumni
 University of Breslau faculty
 Humboldt University of Berlin faculty
 Technical University of Berlin faculty
 Mendelssohn family
 Members of the French Academy of Sciences
 Foreign Members of the Royal Society
 Corresponding Members of the St Petersburg Academy of Sciences
 Members of the Bavarian Maximilian Order for Science and Art