Aspects Of Phenomenology And Cosmology In Heterotic M-Theory

We present an exploration of models of particle phenomenology and cosmology which arise from the E_8 x E_8 heterotic string theory and its strong-coupled limit, known as heterotic M-theory. We first re-examine the B-L MSSM, a realistic supersymmetric extension of the Standard Model, in a more generic region of moduli space. We modify our previous analysis by demanding that the mass scales of the two Wilson lines be simultaneous, and we show that the resulting absence of gauge unification is consistent with string threshold corrections. Using these results, we build a realistic model of inflation where a scalar constructed from the fields of the B-L MSSM is taken to be the inflaton. The subsequent period of reheating is then investigated in detail. Finally, it is known that M-theory admits five-branes, which wrap holomorphic curves upon dimensional compactification. We construct an effective N=1 supersymmetric action to describe the world-volume theory of the resulting three-branes, which live in the bulk space of heterotic M-theory.