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Improved Energy-Momentum Currents in Metric-Affine Spacetime

Ralf Hecht·Friedrich W. Hehl·J. Dermott McCrea·Eckehard W. Mielke·Yuval Ne'eman
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Abstract

In Minkowski spacetime it is well-known that the canonical energy-momentum current is involved in the construction of the globally conserved currents of energy-momentum and total angular momentum. For the construction of conserved currents corresponding to (approximate) scale and proper conformal symmetries, however, an improved energy-momentum current is needed. By extending the Minkowskian framework to a genuine metric-affine spacetime, we find that the affine Noether identities and the conformal Killing equations enforce this improvement in a rather natural way. So far, no gravitational dynamics is involved in our construction. The resulting dilation and proper conformal currents are conserved provided the trace of the energy-momentum current satisfies a (mild) scaling relation or even vanishes.

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Ralf Hecht, Friedrich W. Hehl, J. Dermott McCrea, Eckehard W. Mielke, Yuval Ne'eman. 1992-10-15. Improved Energy-Momentum Currents in Metric-Affine Spacetime. https://doi.org/10.1016/0375-9601(92)90182-l

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