  We present a symmetry-projected configuration mixing scheme to describe
ground and excited states, with well defined quantum numbers, of the
two-dimensional Hubbard model with nearestneighbor hopping and periodic
boundary conditions. Results for the half-filled 2{\times}4, 4{\times}4, and
6{\times}6 lattices, as well as doped 4 {\times} 4 systems, compare well with
available results, both exact and from other state-of-the-art approximations.
We report spectral functions and density of states obtained from a
well-controlled ansatz for the (Ne {\pm} 1)-electron system. Symmetry projected
methods have been widely used for the many-body nuclear physics problem but
have received little attention in the solid state community. Given their
relatively low (mean-field) computational cost and the high quality of results
here reported, we believe that they deserve further scrutiny.
