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We consider a class of inhomogeneous self-similar cosmological models inwhich the perfect fluid flow is tangential to the orbits of a three-parametersimilarity group. We restrict the similarity group to possess both an Abelian$G_{2}$, and a single hypersurface orthogonal Killing vector field, and werestrict the fluid flow to be orthogonal to the orbits of the Abelian $G_{2}$.The temporal evolution of the models is forced to be power law, due to thesimilarity group, and the Einstein field equations reduce to athree-dimensional autonomous system of ordinary differential equations which isqualitatively analysed in order to determine the spatial structure of themodels. The existence of two classes of well-behaved models is demonstrated.The first of these is asymptotically spatially homogeneous and matterdominated, and the second is vacuum dominated and either asymptoticallyspatially homogeneous or acceleration dominated, at large spatial distances.

classical and quantum gravity

Dynamical Equilibrium States of a Class of Irrotational Non-Orthogonally  Transitive $G_{2}$ Cosmologies II: Models With One Hypersurface-Orthogonal  Killing Vector Field