  We propose a deformation principle of gauge theories in three dimensions that
can describe topologically stable self-dual gauge fields, i.e., vacua
configurations that in spite of their masses do not deform the background
geometry and are locally undetected by charged particles. We interpret these
systems as describing boundary degrees of freedom of a self-dual Yang-Mills
field in $2+2$ dimensions with mixed boundary conditions. Some of these fields
correspond to Abrikosov-like vortices with an exponential damping in the
direction penetrating into the bulk. We also propose generalizations of these
ideas to higher dimensions and arbitrary p-form gauge connections.
