Annals of Mathematics · 1957 · 54 citations · 0 references
Natural SciencesMathematicsPhysicsDynamical SystemsMathematical PhysicsTopologyHarmonic AnalysisHilbert Space FormalismLie AlgebrasOperator TheorySpectral TheorySymplectic GeometryOperatorsSimilarity-transformed HamiltonianSpectral DecompositionUnitary OperatorsUnitary RepresentationsVolterra EquationsVolterra Theory