New ultraviolet operators in supersymmetric SO(10) GUT and consistent cosmology

We consider the minimal supersymmetric grand unified model based on the group SO(10) and study conditions leading to possible domain wall formation. It has been shown earlier that the supersymmetry preserving vacuum expectation values (vevs) get mapped to distinct but degenerate set of vevs under action of D parity, leading to formation of domain walls as topological pseudodefects. The metastability of such walls can make them relatively long-lived and contradict standard cosmology. Thus, we are led to consider adding a nonrenormalizable Planck scale suppressed operator that breaks SO(10) symmetry but preserves Standard Model symmetry. For a large range of right-handed breaking scales M-R, this is shown to give rise to the required pressure difference to remove the domain walls without conflicting with consistent big bang nucleosynthesis while avoiding gravitino overproduction. However, if the walls persist till the onset of weak (thermal) inflation, then a low similar to 10-100 TeV M-R becomes problematic.