  We investigate the asymptotic behavior of the eigenvalues of spiked
perturbations of Wigner matrices when the dimension goes to infinity. The
entries of the Hermitian Wigner matrix have a distribution which is symmetric
and satisfies a Poincar\'e inequality. The perturbation matrix is a
deterministic Hermitian matrix whose spectral measure converges to some
probability measure with compact support. We assume that this perturbation
matrix has a fixed number of fixed eigenvalues (spikes) outside the support of
its limiting spectral measure whereas the distance between the other
eigenvalues and this support uniformly goes to zero as the dimension goes to
infinity. We establish that only a particular subset of the spikes will
generate some eigenvalues of the deformed model which will converge to some
limiting points outside the support of the limiting spectral measure. This
phenomenon can be fully described in terms of free probability involving the
subordination function related to the additive free convolution of the limiting
spectral measure of the perturbation matrix by a semi-circular distribution.
Note that up to now only finite rank perturbations had been considered (even in
the deformed GUE case).
