Dynamics of a Vacuum Bianchi Type V Universe with an Arbitrary   Cosmological Constant
  In this paper, we describe the dynamics of a Bianchi Type V vacuum universe with an arbitrary cosmological constant. We begin by using an orthonormal frame approach to write Einstein's field equations as a coupled system of first-order ordinary differential equations. The equilibrium points of the resulting dynamical system are found to be expanding and contracting de Sitter universe solutions, a Minkowski spacetime solution, and static Anti-de Sitter universe solutions, which are characterized by a negative cosmological constant in addition to constant negative spatial curvature. While the expanding de Sitter universe solution is found to be asymptotically stable for $\Lambda > 0$, we also found that the AdS solution is stable for $\Lambda < 0$, as solutions form closed trajectories around it. Further, we show that the different equilibrium points are related to each other by a series of bifurcations of $\Lambda$. 
Ikjyot Singh Kohli
gr-qc math-ph math.DS math.MP