Carl Gustav Jacob Jacobi: Difference between revisions

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[[File:Carl Jacobi2.jpg|thumb|Carl Gustav Jacob Jacobi]]
[[File:Carl Jacobi2.jpg|thumb|Carl Gustav Jacob Jacobi]]


Jacobi was the first to apply elliptic functions to [[number theory]], for example proving [[Pierre de Fermat|Fermat's]] [[Fermat's theorem on sums of two squares|two-square theorem]] and [[Lagrange's four-square theorem]], and similar results for 6 and 8 squares.
Jacobi was the first to apply elliptic functions to [[number theory]], for example proving [[Pierre de Fermat|Fermat's]] [[Fermat's theorem on sums of two squares|two-square theorem]] and [[Lagrange's four-square theorem]],{{sfn|Wolfram|2002|p= 910}} and similar results for 6 and 8 squares.
His other work in number theory continued the work of [[Karl Gauss|C. F. Gauss]]: new proofs of [[quadratic reciprocity]] and introduction of the [[Jacobi symbol]]; contributions to higher reciprocity laws, investigations of [[continued fractions]], and the invention of [[Jacobi sum]]s.
His other work in number theory continued the work of [[Karl Gauss|C. F. Gauss]]: new proofs of [[quadratic reciprocity]] and introduction of the [[Jacobi symbol]]; contributions to higher reciprocity laws, investigations of [[continued fractions]], and the invention of [[Jacobi sum]]s.


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* {{NDB|10|233|234|Jacobi, Carl Gustav Jacob|Christoph J. Scriba|118775766}}
* {{NDB|10|233|234|Jacobi, Carl Gustav Jacob|Christoph J. Scriba|118775766}}
*{{cite journal|last1=Van Vleck|first1=Edward B.|title=Current tendencies of mathematical research|journal=Bulletin of the American Mathematical Society|volume=23|issue=1|year=1916|pages=1–14|issn=0002-9904|doi=10.1090/S0002-9904-1916-02863-1|ref=harv|url=https://www.ams.org/journals/bull/1916-23-01/S0002-9904-1916-02863-1/S0002-9904-1916-02863-1.pdf}}
*{{cite journal|last1=Van Vleck|first1=Edward B.|title=Current tendencies of mathematical research|journal=Bulletin of the American Mathematical Society|volume=23|issue=1|year=1916|pages=1–14|issn=0002-9904|doi=10.1090/S0002-9904-1916-02863-1|ref=harv|url=https://www.ams.org/journals/bull/1916-23-01/S0002-9904-1916-02863-1/S0002-9904-1916-02863-1.pdf}}
*{{cite book|last=Wolfram|first=Stephen|title=A New Kind of Science|publisher=Wolfram Media, Inc.|year=2002|page=[https://www.wolframscience.com/nks/notes-4-4--properties-of-number-theoretic-sequences/ 910]|isbn=1-57955-008-8|url=https://www.wolframscience.com/nks/}}
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Revision as of 10:33, 28 October 2020

Carl Gustav Jacob Jacobi
Königsberg University
ThesisDisquisitiones Analyticae de Fractionibus Simplicibus (1825)
Doctoral advisorEnno Dirksen
Doctoral studentsPaul Gordan
Otto Hesse
Friedrich Julius Richelot

Carl Gustav Jacob Jacobi (

determinants, and number theory. His name is occasionally written as Carolus Gustavus Iacobus Iacobi in his Latin
books, and his first name is sometimes given as Karl.

Jacobi was the first Jewish mathematician to be appointed professor at a German university.[3]

Biography

Jacobi was born of

radicals.[4][5]

In 1821 Jacobi went to study at

curves and surfaces at the University of Berlin.[6][7]

In 1827 he became a professor and in 1829, a tenured professor of

Königsberg University
, and held the chair until 1842.

Jacobi suffered a

Revolution of 1848 Jacobi was politically involved and unsuccessfully presented his parliamentary candidature on behalf of a Liberal club. This led, after the suppression of the revolution, to his royal grant being cut off – but his fame and reputation were such that it was soon resumed. In 1836, he had been elected a foreign member of the Royal Swedish Academy of Sciences
.

Jacobi died in 1851 from a

Johann Encke, the astronomer. The crater Jacobi on the Moon
is named after him.

Scientific contributions

One of Jacobi's greatest accomplishments was his theory of

and the Kepler problem (planetary motion in a central gravitational field).

He also made fundamental contributions in the study of differential equations and to classical mechanics, notably the Hamilton–Jacobi theory.

It was in algebraic development that Jacobi's particular power mainly lay, and he made important contributions of this kind in many areas of mathematics, as shown by his long list of papers in Crelle's Journal and elsewhere from 1826 onwards. He is said to have told his students that when looking for a research topic, one should 'Invert, always invert' ('man muss immer umkehren'), reflecting his belief that inverting known results can open up new fields for research, for example inverting elliptical integrals and focusing on the nature of elliptic and theta functions.[8]

In his 1835 paper, Jacobi proved the following basic result classifying periodic (including elliptic) functions: If a univariate single-valued function is multiply periodic, then such a function cannot have more than two periods, and the ratio of the periods cannot be a real number. He discovered many of the fundamental properties of theta functions, including the functional equation and the

hypergeometric series
.

The solution of the Jacobi inversion problem for the hyperelliptic Abel map by

Weierstrass
in 1854 required the introduction of the hyperelliptic theta function and later the general Riemann theta function for algebraic curves of arbitrary genus. The complex torus associated to a genus algebraic curve, obtained by quotienting by the lattice of periods is referred to as the
Riemann
to arbitrary algebraic curves, may be seen as a higher genus generalization of the relation between elliptic integrals and the Jacobi or Weierstrass elliptic functions.

Carl Gustav Jacob Jacobi

Jacobi was the first to apply elliptic functions to number theory, for example proving Fermat's two-square theorem and Lagrange's four-square theorem,[9] and similar results for 6 and 8 squares. His other work in number theory continued the work of

continued fractions, and the invention of Jacobi sums
.

He was also one of the early founders of the theory of determinants.[10] In particular, he invented the Jacobian determinant formed from the n2 partial derivatives of n given functions of n independent variables, which plays an important part in changes of variables in multiple integrals, and in many analytical investigations. In 1841 he reintroduced the partial derivative ∂ notation of Legendre, which was to become standard.

He was one of the first to introduce and study the symmetric polynomials that are now known as

Grassmannians
.

Students of

operator algebras often encounter the Jacobi identity, the analog of associativity for the Lie bracket
operation.

Planetary theory and other particular dynamical problems likewise occupied his attention from time to time. While contributing to celestial mechanics, he introduced the Jacobi integral (1836) for a sidereal coordinate system. His theory of the last multiplier is treated in Vorlesungen über Dynamik, edited by Alfred Clebsch (1866).

He left many manuscripts, portions of which have been published at intervals in Crelle's Journal. His other works include Commentatio de transformatione integralis duplicis indefiniti in formam simpliciorem (1832), Canon arithmeticus (1839), and Opuscula mathematica (1846–1857). His Gesammelte Werke (1881–1891) were published by the Berlin Academy.

Publications

See also

Notes

  1. ^ Aldrich, John. "Earliest Uses of Symbols of Calculus". Retrieved 20 April 2017.
  2. ^ "Jacobi, Carl Gustav Jacob". Random House Webster's Unabridged Dictionary.
  3. ^ Aderet, Ofer (25 November 2011). "Setting the record straight about Jewish mathematicians in Nazi Germany". Haaretz.
  4. ^ Koenigsberger 1904.
  5. ^ Pierpont 1906, pp. 261–262.
  6. ^ a b Dirichlet 1855, pp. 193–217.
  7. ^ James 2002, pp. 69–74.
  8. ^ Van Vleck 1916, pp. 1–13.
  9. ^ Wolfram 2002, p. 910.
  10. ^ Jacobi 1841, pp. 285–318.

References

External links