No abstract

The spectrum of states of superAuid 4He is described by the representation theory of groups. Starting from the symmetry group, describing the Auctuations of Bose-Einstein condensed states of zero momentum, we have described the, excited states by noncompact groups. This contains complete information about the systems including degeneracy and energy levels, etc. This leads to the possibility of all realistic interactions. As this formalism is equivalent to the Hamiltonian formalism, this description restricts the ambiguous framework of the quantum-mechanical description where interactions or parameters can be viewed arbitrarily. Since we have all possible groups and representations, we can in principle describe all the excited states. Here we are mainly concerned with the phonon spectrum, and the rotonlike and vortex excitations are also taken into consKleratlon.

Sum rules relating the masses of the 1/2+ charmed and uncharmed baryons are derived using weight diagrams.