  A new description is presented for the roton part of the energy spectrum of
supe rfluid ${^4}$He. It is based on the assumption that in addition to the
Feynman density excitations, there exist localized modes which describe
vortex-core elements. The energy spectrum which results from the hybridization
of these two kinds of excitations is compared to the experimental data namely
the structure factor and the scattering cross-section for the single
quasiparticle excitation. Another type of excitation interpreted as a vortex
loop is obtained whose energy agrees both with Raman scattering and critical
velocity experiments.
