  The phases with spontaneously broken symmetries corresponding to
antiferromagnetic and d-wave superconducting order in the two-dimensional
t-t'-Hubbard model are investigated by means of the functional renormalization
group. The introduction of composite boson fields in the magnetic, charge
density and superconducting channels allows an efficient parameterization of
the four-fermion vertex and the study of regimes where either the
antiferromagnetic or superconducting order parameter, or both, are nonzero. We
compute the phase diagram and the temperature dependence of the order parameter
below the critical temperature, where antiferromagnetic and superconductiving
order show a tendency of mutual exclusion.
