Critical phenomena and a new class of self-similar spherically symmetric perfect-fluid solutions - art. no. 081502

We consider the self-similar solutions associated with the critical behavio r observed in the gravitational collapse of spherically symmetric perfect f luids with the equation of state p = alpha mu. We identify for the first ti me the global nature of these solutions and show that it is sensitive to th e value of alpha. In particular, for a >0.28, we show that the critical sol utionis associated with a new class of asymptotically Minkowski self-simila r spacetimes. We discuss some of the implications of this for critical phen omena.