Two quantum quartic anharmonic many-body oscillators are introduced. One of
them is the celebrated Calogero model (rational An model) modified by
quartic anharmonic two-body interactions which support the same symmetry as the
Calogero model. Another model is the three-body Wolfes model (rational G2
model) with quartic anharmonic interaction added which has the same symmetry as
the Wolfes model. Both models are studied in the framework of algebraic
perturbation theory and by the variational method.Comment: 17 pages, LaTeX, 1 figur