635 research outputs found
The American Religious Landscape and the 2004 Presidential Vote: Increased Polarization
Presents findings from a post-election survey conducted in November and December 2004. Explores the polarization between different religions, as well as within the major religious traditions
Religion and American Public Attitudes on War and Peace
In recent years, scholars have discovered that the American public responds to foreign policy issues on the basis of fairly stable broad orientations toward international affairs, influenced by a number of demographic, ideological, and partisan factors. Although there has been much recent speculation about the role that religion plays in shaping such orientations, there are very few empirical analyses of that influence. In this article, I use the 2012 Chicago Council on Global Affairs survey to classify American religious groups on Wittkopf s (1990) classic dimensions of foreign policy attitudes: militant internationalism and cooperative internationalism. I find rather different religious constituencies for each perspective, with Evangelical Protestants and religious traditionalists from other faiths most supportive of militant internationalism, while ethnoreligious minorities and religious modernists are most likely to back cooperative internationalism
Devaluation: a dynamical mechanism for a naturally small cosmological constant
We propose a natural solution to the cosmological constant problem consistent
with the standard cosmology and successful over a broad range of energies. This
solution is based on the existence of a new field, the devaluton, with its
potential modeled on a tilted cosine. After inflation, the universe reheats and
populates the devaluton's many minima. As the universe cools, domain walls form
between different regions. The domain wall network then evolves and sweeps away
regions of higher vacuum energy in favor of lower energy ones. Gravitation
itself provides a cutoff at a minimum vacuum energy, thus leaving the universe
with a small cosmological constant comparable in magnitude to the present day
dark energy density.Comment: 6 pages and prepared in ReV-TeX added notes on eltro-weak breaking
and ds vacu
Observing the Inflaton Potential
We show how observations of the density perturbation (scalar) spectrum and
the gravitational wave (tensor) spectrum allow a reconstruction of the
potential responsible for cosmological inflation. A complete functional
reconstruction or a perturbative approximation about a single scale are
possible; the suitability of each approach depends on the data available.
Consistency equations between the scalar and tensor spectra are derived, which
provide a powerful signal of inflation.Comment: 9 pages, LaTeX, FERMILAB--PUB--93/071--A; SUSSEX-AST 93/4-
Non-Gaussian gravitational clustering field statistics
In this work we investigate the multivariate statistical description of the
matter distribution in the nonlinear regime. We introduce the multivariate
Edgeworth expansion of the lognormal distribution to model the cosmological
matter field. Such a technique could be useful to generate and reconstruct
three-dimensional nonlinear cosmological density fields with the information of
higher order correlation functions. We explicitly calculate the expansion up to
third order in perturbation theory making use of the multivariate Hermite
polynomials up to sixth order. The probability distribution function for the
matter field includes at this level the two-point, the three-point and the
four-point correlation functions. We use the hierarchical model to formulate
the higher order correlation functions based on combinations of the two-point
correlation function. This permits us to find compact expressions for the
skewness and kurtosis terms of the expanded lognormal field which can be
efficiently computed. The method is, however, flexible to incorporate arbitrary
higher order correlation functions which have analytical expressions. The
applications of such a technique can be especially useful to perform
weak-lensing or neutral hydrogen 21 cm line tomography, as well as to directly
use the galaxy distribution or the Lyman-alpha forest to study structure
formation.Comment: 20 pages, 2 figures; accepted in MNRAS 2011 August 22, in original
form 2010 December 14 published, Publication Date: 03/201
Topology of non-linear structure in the 2dF Galaxy Redshift Survey
We study the evolution of non-linear structure as a function of scale in
samples from the 2dF Galaxy Redshift Survey, constituting over 221 000 galaxies
at a median redshift of z=0.11. The two flux-limited galaxy samples, located
near the southern galactic pole and the galactic equator, are smoothed with
Gaussian filters of width ranging from 5 to 8 Mpc/h to produce a continuous
galaxy density field. The topological genus statistic is used to measure the
relative abundance of overdense clusters to void regions at each scale; these
results are compared to the predictions of analytic theory, in the form of the
genus statistic for i) the linear regime case of a Gaussian random field; and
ii) a first-order perturbative expansion of the weakly non-linear evolved
field. The measurements demonstrate a statistically significant detection of an
asymmetry in the genus statistic between regions corresponding to low- and
high-density volumes of the universe. We attribute the asymmetry to the
non-linear effects of gravitational evolution and biased galaxy formation, and
demonstrate that these effects evolve as a function of scale. We find that
neither analytic prescription satisfactorily reproduces the measurements,
though the weakly non-linear theory yields substantially better results in some
cases, and we discuss the potential explanations for this result.Comment: 13 pages, matching proof to be published in MNRAS; new version adds
reference and corrects figure
Effective number of neutrinos and baryon asymmetry from BBN and WMAP
We place constraints on the number of relativistic degrees of freedom and on
the baryon asymmetry at the epoch of Big Bang Nucleosynthesis (BBN) and at
recombination, using cosmic background radiation (CBR) data from the Wilkinson
Microwave Anisotropy Probe (WMAP), complemented by the Hubble Space Telescope
(HST) Key Project measurement of the Hubble constant, along with the latest
compilation of deuterium abundances and measurements of the primordial helium
abundance. The agreement between the derived values of these key cosmological
and particle physics parameters at these widely separated (in time or redshift)
epochs is remarkable. From the combination of CBR and BBN data, we find the
2\sigma ranges for the effective number of neutrinos and for the baryon
asymmetry (baryon to photon number ratio \eta) to be 1.7-3.0 and 5.53-6.76
\times 10^{-10}, respectively.Comment: 10 pages, 10 figures, 2 table
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