Excitations in a Bose-condensed Liquid

Preface 1. Excitations in superfluid 4He: an introduction 2. Dynamic response of helium atoms to thermal neutrons 3. Bose broken symmetry and its implications 4. High momentum scattering and the condensate fraction 5. Dielectric formalism for a Bose fluid 6. Response functions in the low frequency, long wavelength limit 7. Phonons, maxons and rotons 8. Sum rule analysis of the different contributions to dynamic structure analysis 9. Variational and parameterized approaches 10. Two-particle spectrum in Bose-condensed fluids 11. Relation between excitations in liquid and solid helium 12. The new picture: some unsolved problems.