🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPortuguêsРусский한국어中文日本語EntityQ975727· pop 13· linked from 27 articlesDirichlet's principleconcept in potential theoryConnectionsmathematicsEntityCarl Friedrich GaussEntityCategoriesCalculus of variationsHarmonic functionsMathematical principlesPartial differential equations