Deflagration instability in the quark-hadron phase transition

With the aim of determining the scale of inhomogeneities produced by the transition of quarks to hadrons in the early Universe, we study the hydrodynamic stability of slow combustion (deflagration). For a front velocity v, the phase boundary is unstable on a time scale τ∼(1/${\mathit{v}}^3$) fm; surface tension stabilizes bubbles below a critical size. For supercoolings implied by the bubble separations of interest for inhomogeneous nucleosynthesis (∼1 m), τ is much less than the duration of the phase transition. Bubble disruption could restore homogeneous nucleosynthesis.