85,714 research outputs found
The transformation of hunger revisited: estimating available calories from the budgets of late nineteenth-century British households
Levels of nutrition among British worker's households in the late nineteenth century have been much debated. Trevon Logan (2006, 2009) estimated a very low average level of available calories. This paper re-examines the data and finds average levels of available calories much more in line with existing studies, more in line with what is known about energy requirements, and more in line with other aspects of the data. In sum, British households were likely to have been significantly better fed than Logan reports
The significance of the integrated Sachs-Wolfe effect revisited
We revisit the state of the integrated Sachs-Wolfe (ISW) effect measurements
in light of newly available data and address criticisms about the measurements
which have recently been raised. We update the data set previously assembled by
Giannantonio et al. to include new data releases for both the cosmic microwave
background (CMB) and the large-scale structure (LSS) of the Universe. We find
that our updated results are consistent with previous measurements. By fitting
a single template amplitude, we now obtain a combined significance of the ISW
detection at the 4.4 sigma level, which fluctuates by 0.4 sigma when
alternative data cuts and analysis assumptions are considered. We also make new
tests for systematic contaminations of the data, focusing in particular on the
issues raised by Sawangwit et al. Amongst them, we address the rotation test,
which aims at checking for possible systematics by correlating pairs of
randomly rotated maps. We find results consistent with the expected data
covariance, no evidence for enhanced correlation on any preferred axis of
rotation, and therefore no indication of any additional systematic
contamination. We publicly release the results, the covariance matrix, and the
sky maps used to obtain them.Comment: 19 pages, 10 figures. MNRAS in pres
Spectra of Modular and Small-World Matrices
We compute spectra of symmetric random matrices describing graphs with
general modular structure and arbitrary inter- and intra-module degree
distributions, subject only to the constraint of finite mean connectivities. We
also evaluate spectra of a certain class of small-world matrices generated from
random graphs by introducing short-cuts via additional random connectivity
components. Both adjacency matrices and the associated graph Laplacians are
investigated. For the Laplacians, we find Lifshitz type singular behaviour of
the spectral density in a localised region of small values. In the
case of modular networks, we can identify contributions local densities of
state from individual modules. For small-world networks, we find that the
introduction of short cuts can lead to the creation of satellite bands outside
the central band of extended states, exhibiting only localised states in the
band-gaps. Results for the ensemble in the thermodynamic limit are in excellent
agreement with those obtained via a cavity approach for large finite single
instances, and with direct diagonalisation results.Comment: 18 pages, 5 figure
First impressions: introducing the 'Real Times' third sector case studies
‘Real Times’ is the Third Sector Research Centre’s qualitative longitudinal study of third sector organisations, groups and activities. Over a three year period the study is following the fortunes, strategies, challenges and performance of a diverse set of fifteen ‘core’ case studies of third sector activity, and their relations with a number ‘complementary’ case studies. This report introduces the core case studies through summary sketches, and provides a descriptive account of the research up to the end of the first wave of fieldwork
The imprints of the Galactic Bar on the Thick Disk with RAVE
We study the kinematics of a local sample of stars, located within a cylinder of 500 pc radius centered on the Sun, in the RAVE data set. We find clear asymmetries in the v R v∞ velocity distributions of thin and thick disk stars: there are more stars moving radially outward for low azimuthal velocities and more radially inward for high azimuthal velocities. Such asymmetries have been previously reported for the thin disk as being due to the Galactic bar, but this is the first time that the same type of structures are seen in the thick disk. Our findings imply that the velocities of thick-disk stars should no longer be described by Schwarzschilds, multivariate Gaussian or purely axisymmetric distributions. Furthermore, the nature of previously reported substructures in the thick disk needs to be revisited as these could be associated with dynamical resonances rather than to accretion events. It is clear that dynamical models of the Galaxy must fit the 3D velocity distributions of the disks, rather than the projected 1D, if we are to understand the Galaxy fully
Report of the State Budget Crisis Task Force: Final Report
The objective of the State Budget Task Force is to inform the public of the character and gravity of the fiscal issues confronting the states and the consequences of deferring corrective actions. This report culminates three years of research, analysis, and debate. The authors encourage governments at all levels to consider its process recommendations and implement policies and programs that will lead to long-term structural adjustments
Revisiting the WMAP - NVSS angular cross correlation. A skeptic's view
In the context of the study of the ISW, we revisit the angular cross
correlation of WMAP CMB data with the NVSS radio survey. We compute 2-point
cross functions between the two surveys in real and in Fourier space, paying
particular attention on the dependence of results on the flux of NVSS radio
sources, the angular scales where correlations arise and the comparison with
theoretical expectations. We reproduce previous results that claim an excess of
correlation in the angular correlation function (ACF), and we also find some
(low significance) similarity between the CMB and radio galaxy data in the
multipole range \el \in [10, 25]. However, the S/N in the ACFs increases
with higher flux thresholds for NVSS sources, but drops a 30 - 50% in
separations of the order of a pixel size, suggesting some residual point source
contribution. When restricting our analyses to multipoles \el \gt 60, we fail
to find any evidence for cross correlation in the range \el \in [2,10], where
according to the model predictions and our simulations 50% of the S/N is
supposed to arise. Also, the accumulated S/N for \el \lt 60 is below 1, far
from the theoretical expectation of S/N. Part of this disagreement may
be caused by an inaccurate modeling of the NVSS source population: as in
previous works, we find a level of large scale (\el \lt 70) clustering in the
NVSS catalog that seems incompatible with a high redshift population. This is
unlikely to be caused by contaminants or systematics, since it is independent
of flux threshold, and hence present for the brightest () NVSS
sources. Either our NVSS catalogs are not probing the high redshift, large
scale gravitational potential wells, or there is a clear mismatch between the
ISW component present in WMAP data and theoretical expectations.Comment: 16 pages, one extra figure (13 total), matches accepted version in
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