Quantum Mixtures in the Early Universe

In Relativistic Schrödinger Theory for spinning matter, there exist mixtures which have vanishing spin density ($S_{\mu \nu} \equiv 0$). Such a fermionic, but spinless quantum fluid is studied in detail. Its energy- momentum density can develop negative pressure which is able to accelerate the expansion of the universe and to create matter energy through continuous bouncing at minimal radius (``cosmic pumping'').