38,443 research outputs found
A non-perturbative study of matter field propagators in Euclidean Yang-Mills theory in linear covariant, Curci-Ferrari and maximal Abelian gauges
In this work, we study the propagators of matter fields within the framework
of the Refined Gribov-Zwanziger theory, which takes into account the effects of
the Gribov copies in the gauge-fixing quantization procedure of Yang-Mills
theory. In full analogy with the pure gluon sector of the Refined
Gribov-Zwanziger action, a non-local long-range term in the inverse of the
Faddeev-Popov operator is added in the matter sector. Making use of the recent
BRST invariant formulation of the Gribov-Zwanziger framework achieved in [Capri
et al 2016], the propagators of scalar and quark fields in the adjoint and
fundamental representations of the gauge group are worked out explicitly in the
linear covariant, Curci-Ferrari and maximal Abelian gauges. Whenever lattice
data are available, our results exhibit good qualitative agreement.Comment: 27 pages, no figures; V2, minor modifications, to appear in EPJ
Effects of a Cut, Lorentz-Boosted sky on the Angular Power Spectrum
The largest fluctuation in the observed CMB temperature field is the dipole,
its origin being usually attributed to the Doppler Effect - the Earth's
velocity with respect to the CMB rest frame. The lowest order boost correction
to temperature multipolar coefficients appears only as a second order
correction in the temperature power spectrum, . Since v/c - 10-3,
this effect can be safely ignored when estimating cosmological parameters
[4-7]. However, by cutting our galaxy from the CMB sky we induce large-angle
anisotropies in the data. In this case, the corrections to the cut-sky
s show up already at first order in the boost parameter. In this
paper we investigate this issue and argue that this effect might turn out to be
important when reconstructing the power spectrum from the cut-sky data.Comment: 12 pages, 1 figur
A water level relationship between consecutive gauge stations along Solim\~oes/Amazonas main channel: a wavelet approach
Gauge stations are distributed along the Solim\~oes/Amazonas main channel to
monitor water level changes over time. Those measurements help quantify both
the water movement and its variability from one gauge station to the next
downstream. The objective of this study is to detect changes in the water level
relationship between consecutive gauge stations along the Solim\~oes/Amazonas
main channel, since 1980. To carry out the analyses, data spanning from 1980 to
2010 from three consecutive gauges (Tefe, Manaus and Obidos) were used to
compute standardized daily anomalies. In particular for infra-annual periods it
was possible to detect changes for the water level variability along the
Solim\~oes/Amazonas main channel, by applying the Morlet Wavelet Transformation
(WT) and Wavelet Cross Coherence (WCC) methods. It was possible to quantify the
waves amplitude for the WT infra-annual scaled-period and were quite similar to
the three gauge stations denoting that the water level variability are related
to the same hydrological forcing functions. Changes in the WCC was detected for
the Manaus-Obidos river stretch and this characteristic might be associated
with land cover changes in the floodplains. The next steps of this research,
will be to test this hypotheses by integrating land cover changes into the
floodplain with hydrological modelling simulations throughout the time-series
The Brazilian report to the 7th LANDSAT Technical Working Group (LTWG) meeting
Described is the current status of the INPE LANDSAT receiving and processing facilities, as well as the experience in the related activities during the period from June 1984 to February 1985
Real Space Approach to CMB deboosting
The effect of our Galaxy's motion through the Cosmic Microwave Background
rest frame, which aberrates and Doppler shifts incoming photons measured by
current CMB experiments, has been shown to produce mode-mixing in the multipole
space temperature coefficients. However, multipole space determinations are
subject to many difficulties, and a real-space analysis can provide a
straightforward alternative. In this work we describe a numerical method for
removing Lorentz- boost effects from real-space temperature maps. We show that
to deboost a map so that one can accurately extract the temperature power
spectrum requires calculating the boost kernel at a finer pixelization than one
might naively expect. In idealized cases that allow for easy comparison to
analytic results, we have confirmed that there is indeed mode mixing among the
spherical harmonic coefficients of the temperature. We find that using a boost
kernel calculated at Nside=8192 leads to a 1% bias in the binned boosted power
spectrum at l~2000, while individual Cls exhibit ~5% fluctuations around the
binned average. However, this bias is dominated by pixelization effects and not
the aberration and Doppler shift of CMB photons that causes the fluctuations.
Performing analysis on maps with galactic cuts does not induce any additional
error in the boosted, binned power spectra over the full sky analysis. For
multipoles that are free of resolution effects, there is no detectable
deviation between the binned boosted and unboosted spectra. This result arises
because the power spectrum is a slowly varying function of and does not show
that, in general, Lorentz boosts can be neglected for other cosmological
quantities such as polarization maps or higher-point functions.Comment: 8 pages, submitted to MNRA
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