Computations of the Growth of Hadronic Bubbles During the Cosmological Quark-Hadron Transition

In a previous paper, we presented an analysis of the hydrodynamics of bubble growth during the cosmological quark-hadron transition. After a brief review of the relevant system of equations, we here describe computations which follow the growth of a single spherical hadron bubble within an initially uniform quark medium. Our computer code uses a standard Lagrangian finite-difference scheme for flow within each phase together with continuous tracking of the phase interface across the grid by means of a characteristic method with an iterative solution of the junction conditions. Results are presented which are relevant for the early stages of bubble growth and a connection with asymptotic similarity solutions is demonstrated.