Mathematician:Johann Peter Gustav Lejeune Dirichlet

Mathematician
Full name: Johann Peter Gustav Lejeune Dirichlet.

German mathematician who worked mainly in the field of analysis.

Credited with the first formal definition of a function. Married Rebecka Mendelssohn, the youngest sister of Fanny and Felix Mendelssohn.

Nationality
German, although born in what was then part of the French empire.

History

 * Born: 13 Feb 1805, Düren, French Empire (now Germany)
 * Died: 5 May 1859, Göttingen, Hanover (now Germany)

Theorems and Definitions

 * Theorems named Dirichlet's Theorem:
 * Dirichlet's Approximation Theorem (Diophantine Equations)
 * Dirichlet's Theorem on Arithmetic Progressions (Number Theory, specifically prime numbers)
 * Dirichlet's Unit Theorem (Algebraic Number Theory and Ring Theory)


 * Dirichlet Beta Function


 * Dirichlet Tessellation (also known as a Voronoi Diagram) and hence:
 * Dirichlet Cell
 * Dirichlet Polygon


 * Dirichlet Character in Number Theory, specifically:
 * Dirichlet Series (Analytic Number Theory)
 * Dirichlet L-function


 * Dirichlet Conditions (for Fourier Series)
 * Dirichlet Convolution (Number Theory and Arithmetic Functions)
 * Dirichlet Density (Number Theory)
 * Dirichlet Distribution (Probability Theory)
 * Generalized Dirichlet Distribution
 * Dirichlet Process
 * Dirichlet Form
 * Dirichlet Kernel (Functional Analysis, Fourier Series)
 * Dirichlet Problem (Partial Differential Equations)
 * Dirichlet Stability Criterion (Dynamical Systems Theory)
 * Dirichlet's Test for Uniform Convergence (Analysis)
 * Dirichlet Boundary Condition (Differential Equations)
 * Dirichlet Function (Topology)
 * Pigeonhole Principle (also known as Dirichlet's Box (or Drawer) Principle (Combinatorics)
 * Dirichlet Divisor Problem (currently unsolved) (Number Theory)
 * Dirichlet Eta Function (Number Theory)
 * Latent Dirichlet Allocation (Statistics)
 * Class Number Formula (Analysis)
 * Dirichlet Integral (Integral Calculus)
 * Dirichlet's Principle (Harmonic Functions) (Mathematical Physics)

Books and Papers

 * 1863: Vorlesungen über Zahlentheorie

Also known as
Some sources refer to him as Peter Dirichlet.