4,204 research outputs found
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
Scalar Field Equations from Quantum Gravity during Inflation
We exploit a previous computation of the self-mass-squared from quantum
gravity to include quantum corrections to the scalar evolution equation. The
plane wave mode functions are shown to receive no significant one loop
corrections at late times. This result probably applies as well to the inflaton
of scalar-driven inflation. If so, there is no significant correction to the
correlator that plays a crucial role in computations of the power
spectrum.Comment: 19 pages, 5 table
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
Graviton Loop Corrections to Vacuum Polarization in de Sitter in a General Covariant Gauge
We evaluate the one-graviton loop contribution to the vacuum polarization on
de Sitter background in a 1-parameter family of exact, de Sitter invariant
gauges. Our result is computed using dimensional regularization and fully
renormalized with BPHZ counterterms, which must include a noninvariant owing to
the time-ordered interactions. Because the graviton propagator engenders a
physical breaking of de Sitter invariance two structure functions are needed to
express the result. In addition to its relevance for the gauge issue this is
the first time a covariant gauge graviton propagator has been used to compute a
noncoincident loop. A number of identities are derived which should facilitate
further graviton loop computations.Comment: 61 pages, 1 figure, 11 tables, version 2 (63 pages) revised for
publication in CQ
One loop graviton corrections to dynamical photons in de Sitter
We employ a recent, general gauge computation of the one loop graviton
contribution to the vacuum polarization on de Sitter to solve for one loop
corrections to the photon mode function. The vacuum polarization takes the form
of a gauge independent, spin 2 contribution and a gauge dependent, spin 0
contribution. We show that the leading secular corrections derive entirely from
the spin 2 contribution.Comment: 41 pages, no figures, uses LaTeX2
Single Graviton Loop Contribution to the Self-Mass of a Massless, Conformally Coupled Scalar on de Sitter Background
We use a simplified formalism to re-compute the single graviton loop
contribution to the self-mass of a massless, conformally coupled scalar on de
Sitter background which was originally made by Boran, Kahya and Park [1-3]. Our
result resolves the problem with the flat space correspondence limit that was
pointed out by Fr\"ob [4]. We discuss how this computation will be used in a
long-term project to purge the linearized effective field equation of gauge
dependence.Comment: 26 pages, 1 figure, uses LaTeX 2e. Version 2 revised slightly for
publicatio
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