4,437 research outputs found
Linearized Weyl-Weyl Correlator in a de Sitter Breaking Gauge
We use a de Sitter breaking graviton propagator to compute the tree order
correlator between noncoincident Weyl tensors on a locally de Sitter
background. An explicit, and very simple result is obtained, for any spacetime
dimension D, in terms of a de Sitter invariant length function and the tensor
basis constructed from the metric and derivatives of this length function. Our
answer does not agree with the one derived previously by Kouris, but that
result must be incorrect because it not transverse and lacks some of the
algebraic symmetries of the Weyl tensor. Taking the coincidence limit of our
result (with dimensional regularization) and contracting the indices gives the
expectation value of the square of the Weyl tensor at lowest order. We propose
the next order computation of this as a true test of de Sitter invariance in
quantum gravity.Comment: 31 pages, 2 tables, no figures, uses LaTex2
One Loop Corrected Mode Functions for SQED during Inflation
We solve the one loop effective scalar field equations for spatial plane
waves in massless, minimally coupled scalar quantum electrodynamics on a
locally de Sitter background. The computation is done in two different gauges:
a non-de Sitter invariant analogue of Feynman gauge, and in the de Sitter
invariant, Lorentz gauge. In each case our result is that the finite part of
the conformal counterterm can be chosen so that the mode functions experience
no significant one loop corrections at late times. This is in perfect agreement
with a recent, all orders stochastic prediction.Comment: 26 pages, uses LaTeX 2 epsilon, no figures, version 2 has an updated
reference lis
Improving the Single Scalar Consistency Relation
We propose a test of single-scalar inflation based on using the well-measured
scalar power spectrum to reconstruct the tensor power spectrum, up to a single
integration constant. Our test is a sort of integrated version of the
single-scalar consistency relation. This sort of test can be used effectively,
even when the tensor power spectrum is measured too poorly to resolve the
tensor spectral index. We give an example using simulated data based on a
hypothetical detection with tensor-to-scalar ratio . Our test can
also be employed for correlating scalar and tensor features in the far future
when the data is good.Comment: 16 pages, 1 figure, uses LaTeX2e version 2 extensively revised for
publicatio
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