Graviton propagator in a 2-parameter family of de Sitter breaking gauges

Abstract

We formulate the graviton propagator on de Sitter background in a 2parameter family of simple gauges which break de Sitter invariance. Explicit results are derived for the first order perturbations in each parameter. These results should be useful in computations to check for gauge dependence of graviton loop corrections.

How Inflationary Gravitons Affect Gravitational Radiation

“…The new technique was implemented at one loop order for quantum gravitational corrections to a massless scalar on flat space background to derive a result which is indpendent of the gauge parameters α and β [49]. The same technique has just been applied to quantum gravitational corrections to electrodynamics on flat space background [51], and strenuous efforts are underway to generalize it to de Sitter background [52]. The two flat space exercises demonstrate that gauge independent results typically show the same spacetime dependence as in a fixed gauge, but with different numerical coefficients.…”

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“…Then we will apply the Donoghue construction in the simple gauge [25,26] to work out reliable coefficient for the large logarithms. To explicitly demonstrate gauge independence, we plan to re-do the entire analysis in a 2-parameter family of generalizations to the simple gauge propagator [38].…”

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