Gustav Peter Lejeune Dirichlet

Abstract

Dirichlet was born on February 13, 1805, in Düren, a town midway between Aachen und Cologne, where his father was town postmaster. His grandfather was a textile manufacturer from the nearby French-speaking Belgian town Richelet, so that the origin of the family name Lejeune Dirichlet is easily explained as “Young from Richelet”. His parents provided him with a good education, sending him in 1817 to the Gymnasium in Bonn and two years later to the Jesuit College in Cologne. At the age of sixteen he completed the Abitur. Already during his schooling Dirichlet had developed a passion for mathematics that determined him to study this domain at the university. But since, at that time, the level of teaching at German universities was low, he went to Paris, then the centre of mathematics with such eminent scientists as Fourier, Lacroix, Laplace, Legendre and Poisson. Dirichlet came in closer contact with some of them, in particular his contacts with Fourier became important for his later research. But even more important was his study of Gauss’s Disquisitiones arithmeticae. He was the first to understand this fundamental work in number theory, which he simplified in his later lectures in Berlin, subsequently published by Dedekind.