On string cosmology and the RG flow in 2D field theory

Time-dependent solutions of bosonic string theory resemble renormalisation group trajectories in the space of 2D field theories: they often interpolate between repulsive and attractive static solutions. It is shown that the attractive static solutions are those whose spatial sections are minima of vertical stroke c-25 vertical stroke , where c is the ''c-function''. The size of the domain of attraction of such a solution may be a measure of the probability of the corresponding string vacuum. Our discussion has also an implication for the RG flow in theories coupled to dynamical 2D gravity: the flow from models with c>25 to models with c<25 is forbidden. ((orig.))