Domain walls and magnetic monopoles in Grand Unified Models

Motivated by Grand Unification, we study the formation of magnetic monopoles in an SU(3) non-Abelian gauge theory. We find that the number density of magnetic monopoles depends critically on a parameter, $\epsilon$, that controls the abundance and subsequent decay of biased domain walls. For sufficiently small but non-vanishing values of $\epsilon$, very few monopoles and walls survive in our simulations, potentially solving the cosmological monopole over-abundance problem. In addition, the scenario predicts a stochastic gravitational background from biased domain walls and the possibility of magnetically charged black holes.