🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPolskiPortuguêsРусскийفارسی한국어中文日本語EntityQ1972470· pop 19· linked from 571 articlesunitary operatorsurjective bounded operator on a Hilbert space preserving the inner productAvailable in 19 languagesEspañolFrançaisDeutsch中文日本語РусскийPortuguêsItalianoCatalanCzechEsperantoConnectionsinner product spaceEntitybounded operatorEntityCategoriesLinear operatorsOperator theoryUnitary operators