EntityQ6415019· pop 5· linked from 5 articlesKirchhoff integral theoremSign in to saveMethod to solve scalar wave equationConnectionsHuygens–Fresnel principleEntityGreen's identitiesEntityInternational Standard Book NumberEntityintegralEntitysurfaceEntityvector calculusEntityspherical coordinate systemEntitywave equationEntityunit vectorEntitysolid angleEntitynormalEntityscalar fieldEntitywavenumberEntitywavefrontEntityphasorEntitysurface integralEntityHelmholtz equationEntitydirectional derivativeEntityvolume integralEntityFourier inversion theoremEntityCategoriesDiffractionGustav KirchhoffPhysical optics