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arXiv · 1805.11626

Gravity with more or less gauging

Steffen Gielen·Rodrigo de Leon Ardon·Roberto Percacci
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Abstract

General Relativity is usually formulated as a theory with gauge invariance under the diffeomorphism group, but there is a 'dilaton' formulation where it is in addition invariant under Weyl transformations, and a 'unimodular' formulation where it is only invariant under the smaller group of special diffeomorphisms. Other formulations with the same number of gauge generators, but a different gauge algebra, also exist. These different formulations provide examples of what we call 'inessential gauge invariance', 'symmetry trading' and 'linking theories'; they are locally equivalent, but may differ when global properties of the solutions are considered. We discuss these notions in the Lagrangian and Hamiltonian formalism.

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Steffen Gielen, Rodrigo de Leon Ardon, Roberto Percacci. 2018-08-28. Gravity with more or less gauging. https://doi.org/10.1088/1361-6382%2Faadbd1

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