Two-fluid evolving Lorentzian wormholes

We investigate the evolution of a family of wormholes sustained by two matter components: one with homogeneous and isotropic properties (t) and another inhomogeneous and anisotropic ₈₍ (t, r). The rate of expansion of these evolving wormholes is only determined by the isotropic and homogeneous matter component (t). Particularly, we consider a family of exact two-fluid evolving wormholes expanding with constant velocity and satisfying the dominant and the strong energy conditions in the whole space-time. In general, for the case of vanishing isotropic fluid (t) and cosmological constant the space expands with constant velocity, and for (t) =0 and 0 the rate of expansion is determined by the cosmological constant. The considered here two-fluid evolving wormholes are a generalization of single fluid models discussed in previous works of the present authors Phys. Rev. D 78, 104006 (2008) ; Phys. Rev. D 79, 024005 (2009).