EntityQ4138816· pop 8· linked from 22 articleshypoelliptic operatorSign in to savePartial differential operatorConnectionsInternational Standard Book NumberEntitypartial differential equationEntitywave equationEntityopen setEntityLaplace operatorEntityheat equationEntitydistributionEntitysmooth functionEntityPlanetMathEntitydifferential operatorEntityelliptic operatorEntityCategoriesDifferential operatorsPartial differential equations