Peter Gustav Lejeune Dirichlet

Johann Peter Gustav Lejeune Dirichlet [ləˈʒœn diʀiˈkle] (February 13, 1805 – May 5, 1859) was a German mathematician credited with the modern definition of the function .

His family came from the town of Richelette in Belgium, from which his surname "Lejeune Dirichlet" ("le jeune de Richelette") is derived.

Dirichlet was born in Düren, where his father was a postmaster. He was educated in Germany, then in France, where he learned from most of the well-known mathematicians of the time. He also learned from Georg Ohm . His first paper was on Fermat's last theorem which included part of a proof for the case ${\displaystyle n=5}$, completed by Adrien-Marie Legendre. Dirichlet also completed his proof at about the same time; he then gave the complete solution for the case ${\displaystyle n=14}$.

In 1831 he married Rebecca Henriette Mendelssohn Bartholdy, a girl from a prominent family who had converted from Judaism to Christianity ; she was the granddaughter of the philosopher Moses Mendelssohn, the daughter of Abraham Mendelssohn Bartholdy, and the sister of the composers Felix Mendelssohn Bartholdy and Fanny Mendelssohn.

Ferdinand Eisenstein, Leopold Kronecker, and Rudolf Lipschitz were his students. After his death, Dirichlet's lectures and other results in arithmetic were collected, edited, and published by his colleague and friend, the mathematician Richard Dedekind, under the title Vorlesungen über Zahlentheorie (Lectures on Arithmetic )

• The Life and Work of Gustav Lejeune Dirichlet (1805–1859) Archived 2021-05-22 at the Wayback Machine by Jürgen Elstrodt.
• Peter Gustav Lejeune Dirichlet at the Mathematics Genealogy Project .
• Dirichlet, Johann Peter Gustav Lejeune, Vorlesungen über Zahlentheorie. Braunschweig Vorlesungen über Zahlentheorie. Braunschweig, 1863. " Number Theory for the Millennium Archived 2006-11-16 at the Wayback Machine ".
• Biography of Dirichlet found at Fermat's Last Theorem Blog .