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Bianchi-I classical and quantum spinor cosmology with signature change

B. Vakili·H. R. Sepangi
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Abstract

We study the classical and quantum evolution of a universe in which the matter source is a massive Dirac spinor field and the universe is described by a Bianchi type I metric. We focus attention on those classical solutions that admit a degenerate metric in which the scale factors have smooth behavior in transition from a Euclidean to a Lorentzian domain and show that this transition happens when the cosmological constant, $Λ$, is negative. The resulting quantum cosmology and the corresponding Wheeler-DeWitt equation are also studied and closed form expressions for the wave functions of the universe is presented. We have shown that there is a close relationship between the quantum states and signature changing classical solutions, suggesting a mechanism for creation of a Lorentzian universe from a Euclidean region by a continuous change of signature. The quantum solutions also represent a quantization rule for the mass of the spinor field.

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B. Vakili, H. R. Sepangi. 2005-09-10. Bianchi-I classical and quantum spinor cosmology with signature change. https://doi.org/10.1088/1475-7516%2F2005%2F09%2F008

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