A universe with torsion
Dipartimento di Scienze Fisiche - Mostra d'Oltremare, Pad. 19, 80125 Napoli, Italy.
Accepted: 13 February 1997
In the context of the ECSK theory of gravitation we have obtained the solutions of the Einstein-Dirac equations in a Friedmann-Robertson-Walker spatially flat universe when spin has only one non-zero space-component. All solutions are singular: one of these is bounded and describes a universe whose lifetime is , independently of initial conditions; the others describe a spatially flat open expanding or contracting universe, where spin increases the expansion rate or the contraction rate, respectively, of the universe for time intervals in a neighbourhood of the singularities.
PACS: 04.50.+h – Gravity in more than four dimensions, Kaluza-Klein theory, unified field theories; alternative theories of gravity / 98.80.-k – Cosmology
© EDP Sciences, 1997