banachspaces basis<mathematik> congresses diskrepanz feynmanintegrals fractals functional funktionenraum integration isometrics(mathematics) linearoperators lineartopologicalspaces littlewood-paleytheory measuretheory numerischeintegration operator-valuedmeasures partialdifferentialoperators spectraltheory(mathematics) stochasticanalysis stochasticdifferentialequations systemanalysis vector-valuedmeasures wienerintegrals