DIFFUSE DOMAIN-WALLS AND INTERSECTING FLAT DIRECTIONS

It is shown that novel kinds of cosmological structures can arise if t here are flat (or almost flat) directions of the scalar potential that intersect each other, as happens in some simple supersymmetric models . One example is ''diffuse domain walls'' whose energy density is only of order T-4. It is shown that as the universe expands the scale of t he domains themselves remains of the order of the horizon scale, while the energy in the diffuse walls remains a roughly fixed fraction of t he energy in matter.