Effective Supergravity from Heterotic M-Theory and its Phenomenological Implications

In this talk I summarize several recent results concerning the four-dimensional effective supergravity obtained using a Calabi-Yau compactification of the $E_8\times E_8$ heterotic string from M-theory. A simple macroscopic study is provided expanding the theory in powers of two dimensionless variables. Higher order terms in the K\"ahler potential are identified and matched with the heterotic string corrections. In the context of this M-theory expansion, I discuss several phenomenological issues: universality of soft scalar masses, relations between the different scales of the theory (eleven-dimensional Planck mass, compactification scale and orbifold scale) in order to obtain unification at $3\times 10^{16}$ GeV or lower values, soft supersymmetry-breaking terms, and finally charge and colour breaking minima. The above analyses are also carried out in the presence of (non-perturbative) five-branes.