🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPolskiPortuguêsSvenskaРусскийفارسی한국어中文日本語EntityQ1357684· pop 20· linked from 467 articlesRiesz representation theoremtheoremAvailable in 19 languagesEspañolFrançaisDeutsch中文日本語РусскийPortuguêsItalianoCatalanConnectionslinear mapEntityinner product spaceEntityCategoriesDuality (mathematics)Hilbert spacesIntegral representationsLinear functionalsTheorems in functional analysis