Based on the nontopological soliton model, we discuss the quark-hadron phase transition of the early Universe in the hot big-bang model. We extract the parameter spaces which are relevant for small supercooling of the phase transition and the inhomogeneous nucleosynthesis. In particular, we explore the possibility that the early Universe is a cold universe filled with very dense and degenerate baryons. This cold universe is then reheated by the latent heat released from the quarkhadron phase transition. Without fine-tuning any parameter in the soliton model, we find that a typical potential in the model would dilute the dense baryons to an acceptable baryon asymmetry of the Universe. We also discuss the generation of density fluctuations during the phase transition in the cold universe.
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