4,322 research outputs found
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
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
Quantum Gravity Corrections to the One Loop Scalar Self-Mass during Inflation
We compute the one loop corrections from quantum gravity to the
self-mass-squared of a massless, minimally coupled scalar on a locally de
Sitter background. The calculation was done using dimensional regularization
and renormalized by subtracting fourth order BPHZ counterterms. Our result
should determine whether quantum gravitational loop corrections can
significantly alter the dynamics of a scalar inflaton.Comment: 47 pages, 3 figures, 20 tables, uses LaTeX 2 epsilon, version 2
revised for publication in Physical Review
Charged Scalar Self-Mass during Inflation
We compute the one loop self-mass of a charged massless, minimally coupled
scalar in a locally de Sitter background geometry. The computation is done in
two different gauges: the noninvariant generalization of Feynman gauge which
gives the simplest expression for the photon propagator and the de Sitter
invariant gauge of Allen and Jacobson. In each case dimensional regularization
is employed and fully renormalized results are obtained. By using our result in
the linearized, effective field equations one can infer how the scalar responds
to the dielectric medium produced by inflationary particle production. We also
work out the result for a conformally coupled scalar. Although the conformally
coupled case is of no great physical interest the fact that we obtain a
manifestly de Sitter invariant form for its self-mass-squared establishes that
our noninvariant gauge introduces no physical breaking of de Sitter invariance
at one loop order.Comment: 41 pages, LaTeX 2epsilon, 3 figures, uses axodra
Two Loop Scalar Bilinears for Inflationary SQED
We evaluate the one and two loop contributions to the expectation values of
two coincident and gauge invariant scalar bilinears in the theory of massless,
minimally coupled scalar quantum electrodynamics on a locally de Sitter
background. One of these bilinears is the product of two covariantly
differentiated scalars, the other is the product of two undifferentiated
scalars. The computations are done using dimensional regularization and the
Schwinger-Keldysh formalism. Our results are in perfect agreement with the
stochastic predictions at this order.Comment: 43 pages, LaTeX 2epsilon, 5 figures (using axodraw.sty) Version 2 has
updated references and important corrections to Tables 3-5 and to eqns
(139-141), (145-146), (153-155), (158) and (160
Measured spacecraft dynamic effects on atmospheric science instruments
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77045/1/AIAA-1997-419-842.pd
General plane wave mode functions for scalar-driven cosmology
We give a solution for plane wave scalar, vector and tensor mode functions in
the presence of any homogeneous, isotropic and spatially flat cosmology which
is driven by a single, minimally coupled scalar. The solution is obtained by
rescaling the various mode functions so that they reduce, with a suitable scale
factor and a suitable time variable, to those of a massless, minimally coupled
scalar. We then express the general solution in terms of co-moving time and the
original scale factor.Comment: 6 pages, revtex4, no figures, revised version corrects an
embarrassing mistake (in the published version) for the parameter q_C.
Affected eqns are 45 and 6
The Coincidence Limit of the Graviton Propagator in de Donder Gauge on de Sitter Background
We explicitly work out the de Sitter breaking contributions to the recent
solution for the de Donder gauge graviton propagator on de Sitter. We also
provide explicit power series expansions for the two structure functions, which
are suitable for implementing dimensional regularization. And we evaluate the
coincidence limit of the propagator.Comment: 41 pages, uses LaTeX 2e, version 2 has some typoes correcte
Carrion Beetles (Coleoptera: Silphidae) of the Konza Prairie Biological Station
Pitfall traps were used to determine diversity, seasonality, and numbers of burying beetles on the Konza Prairie Biological Station (KPBS) during the summers of 1997 and 1998. Traps were baited with either beef liver (1997) or whole mouse carcasses (1997 and 1998); significantly more carrion beetles were found in traps baited with carcasses. A total of 1003 carrion beetles, representing 8 species, were trapped over the course of 1556 trap nights. One of these species, Necrophila americana Linneaus, had not previously been recorded in Riley County. One additional species was found at sites where pitfall trap bait was discarded, bringing the total number of KPBS silphid species to 9. Bait age was an important determinant in attracting silphids to pitfall traps, as numbers of beetles in the trap continued to increase with bait age up to 6 days. Grassland topography (upland vs. lowland trap sites) significantly affected the numbers of carrion beetles trapped. Grassland bum history did not affect number of carrion beetles trapped, but did seem to influence species diversit
Solving the Effective Field Equations for the Newtonian Potential
Loop corrections to the gravitational potential are usually inferred from
scattering amplitudes, which seems quite different from how the linearized
Einstein equations are solved with a static, point mass to give the classical
potential. In this study we show how the Schwinger-Keldysh effective field
equations can be used to compute loop corrections to the potential in a way
which parallels the classical treatment. We derive explicit results for the one
loop correction from the graviton self-energy induced by a massless, minimally
coupled scalar.Comment: 15 pages, uses LaTeX2
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