| In this dissertation we study the following topics: compactification of M-theory on a special class of G2 holonomy spaces, the nonabelian gauge fields that this produces in four dimensions and the dual description of the original 11-dimensional background in terms of systems of intersecting D-branes in type IIA and type IIB string theory; N = 2 hypermultiplets coupled to supergravity: description in terms of the corresponding hyperkähler cones rather than quaternion-Kähler spaces; domain walls in gauged N = 2 D = 5 supergravity, including Randall-Sundrum ones; massive gravitino propagator in maximally symmetric spaces in terms of intrinsic geometric objects and issues in dS/CFT correspondence. |
