Nonlinear spinor field in Bianchi type-I cosmology: Inflation, isotropization, and late time acceleration

A self-consistent system of interacting nonlinear spinor and scalar fields within the scope of a Bianchi type-I cosmological model filled with perfect fluid is considered. Exact self-consistent solutions to the corresponding field equations are obtained. A role of the spinor field in the evolution of the Universe is studied. It is shown that the spinor field gives rise to an accelerated mode of expansion of the Universe. Early in the evolution, the spinor field nonlinearity generates an accelerated mode of expansion. The rapid growth of the Universe in this case results in the earlier isotropization. At the later evolution the acceleration of the Universe is provided with a spinor mass.

Figure 1

View of the potential $\mathcal{U}(\tau )$ for $\lambda >0$.

Figure 2

View of the potential $\mathcal{U}(\tau )$ for a negative $\lambda$.

Figure 3

Energy density and pressure corresponding to a positive $\lambda$.

Figure 4

Energy density and pressure in case of a negative $\lambda$.

Figure 5

Acceleration of the Universe corresponding to a positive $\lambda$.

Figure 6

Acceleration of the Universe in case of a negative $\lambda$.

Figure 7

Deceleration parameter corresponding to a positive $\lambda$.

Figure 8

Deceleration parameter in case of a negative $\lambda$.