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Classical and quantum spinor cosmology with signature change

B. Vakili·S. Jalalzadeh·H. R. Sepangi
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Abstract

We study the classical and quantum cosmology of a universe in which the matter source is a massive Dirac spinor field and consider cases where such fields are either free or self-interacting. We focus attention on the spatially flat Robertson-Walker cosmology and classify the solutions of the Einstein-Dirac system in the case of zero, negative and positive cosmological constant $Λ$. For $Λ<0$, these solutions exhibit signature transitions from a Euclidean to a Lorentzian domain. In the case of massless spinor fields it is found that signature changing solutions do not exist when the field is free while in the case of a self-interacting spinor field such solutions may exist. The resulting quantum cosmology and the corresponding Wheeler-DeWitt equation are also studied for both free and self interacting spinor fields and closed form expressions for the wavefunction of the universe are presented. These solutions suggest a quantization rule for the energy.

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B. Vakili, S. Jalalzadeh, H. R. Sepangi. 2005-05-14. Classical and quantum spinor cosmology with signature change. https://doi.org/10.1088/1475-7516%2F2005%2F05%2F006

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