Na današnji dan rođen je Lejeune Dirichlet (1805-1859). Njemački matematičar, zet Felixa Mendelssohna, Kroneckerov i Lipschitzov učitelj. Čuli ste za Dirichletov princip (imate 5 jabuka u 4 korpe - u bar jednoj korpi se nalazi više od jedne jabuke). Wikipedija daje spisak pojmova u matematici koji nose Dirichletovo ime:
* Theorems named Dirichlet's theorem:
o Dirichlet's approximation theorem (diophantine approximation)
o Dirichlet's theorem on arithmetic progressions (number theory, specifically prime numbers)
o Dirichlet's unit theorem (algebraic number theory and rings)
* Dirichlet beta function
* Dirichlet cell, polygon
* Dirichlet characters (number theory, specifically Zeta and L-functions. 1831)
* Dirichlet conditions (Fourier series)
* Dirichlet convolution (number theory and Arithmetic functions)
* Dirichlet density (number theory)
* Dirichlet distribution (probability theory)
* Dirichlet form
* Dirichlet kernel (functional analysis, Fourier series)
* Dirichlet problem (partial differential equations)
* Dirichlet series (analytic number theory)
* Dirichlet stability criterion (Dynamical systems)
* Dirichlet's test (analysis)
* Dirichlet tessellation, also called a Voronoi diagram (geometry)
* Dirichlet boundary condition (differential equations)
* Dirichlet function (topology)
* Pigeonhole principle/Dirichlet's box (or drawer) principle (combinatorics)
* Dirichlet divisor problem (currently unsolved) (Number theory)
* Dirichlet eta function (number theory)
* Latent Dirichlet allocation
* Class number formula
* Dirichlet integral
* Dirichlet principle
* Generalized Dirichlet distribution (probability theory)
* Dirichlet process
Na današnji dan umro je Marian Rejewski (1905-1980). Poljski matematičar, izvršio prvu sistematsku dekripciju njenačkog Enigma sistema šifriranja.
Ako neko poželi, danas ću još pisati o Enigmi.