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First-order symmetric-hyperbolic Einstein equations with arbitrary fixed gauge

Simonetta Frittelli·Oscar A. Reula
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Abstract

We find a one-parameter family of variables which recast the 3+1 Einstein equations into first-order symmetric-hyperbolic form for any fixed choice of gauge. Hyperbolicity considerations lead us to a redefinition of the lapse in terms of an arbitrary factor times a power of the determinant of the 3-metric; under certain assumptions, the exponent can be chosen arbitrarily, but positive, with no implication of gauge-fixing.

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Simonetta Frittelli, Oscar A. Reula. 1996-05-01. First-order symmetric-hyperbolic Einstein equations with arbitrary fixed gauge. https://doi.org/10.1103/physrevlett.76.4667

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