Peter Gustav Lejeune DirichletDied 5 May 1859 at age 54 (born 13 Feb 1805).German mathematician who made valuablecontributionscontributions to number theory, analysis, and mechanics. Dirichlet is best known for his papers on conditions for the convergence of trigonometric series and the use of the series to represent arbitrary functions. He also proposed in 1837 the modern definition of a function. In mechanics he investigated the equilibrium of systems and potential theory. This led him to the Dirichlet problem concerning harmonic functions with given boundary conditions. Dirichlet is considered the founder of the theory of Fourier series, having corrected the earlier mistakes of other workers on Fourier's writings. One of his students was Riemann. In 1855, he succeeded Carl Friedrich Gauss at the University of Göttingen. |
