  The interplay between quadrupole and octupole degrees of freedom is discussed
in a series of U, Pu, Cm and Cf isotopes both at the mean-field level and
beyond. In addition to the static Hartree-Fock-Bogoliubov approach, dynamical
beyond-mean-field correlations are taken into account via both parity
restoration and symmetry-conserving Generator Coordinate Method calculations
based on the parametrization D1M of the Gogny energy density functional.
Physical properties such as correlation energies, negative-parity excitation
energies as well as reduced transition probabilities $B(E1)$ and $B(E3)$ are
discussed in detail and compared with the available experimental data. It is
shown that, for the studied nuclei, the quadrupole-octupole coupling is weak
and to a large extent the properties of negative parity states can be
reasonably well described in terms of the octupole degree of freedom alone.
