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On the origin of the difference between time and space

C. Wetterich
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Abstract

We suggest that the difference between time and space is due to spontaneous symmetry breaking. In a theory with spinors the signature of the metric is related to the signature of the Lorentz-group. We discuss a higher symmetry that contains pseudo-orthogonal groups with arbitrary signature as subgroups. The fundamental asymmetry between time and space arises then as a property of the ground state rather than being put into the formulation of the theory a priori. We show how the complex structure of quantum field theory as well as gravitational field equations arise from spinor gravity - a fundamental spinor theory without a metric.

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C. Wetterich. 2004-05-25. On the origin of the difference between time and space. https://doi.org/10.1103/physrevlett.94.011602

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