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## CONTRIBUTION TO THE THEORY OF PERMEABILITY OF MEMBRANES FOR ELECTROLYTES

Fonte: The Rockefeller University Press
Publicador: The Rockefeller University Press

Tipo: Artigo de Revista Científica

Publicado em 04/01/1926
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On page 39, Vol. viii, No. 2, September 18, 1925, multiply the right-hand side of formula (2) by the factor See PDF for Equation. On page 44, immediately after formula (1) the text should be continued as follows: Let us suppose a membrane to be separated by two solutions of KCl of different concentrations K1 and K2 and these concentrations and the corresponding concentrations of K+ within the membrane, which are in equilibrium with the outside solutions, to be so high that the H+ ions may be neglected. When a small electric current flows across the system, practically the K+ ions alone are transferred and that in a reversible manner. Therefore the total P.D. is practically See PDF for Equation This P.D. is composed of two P.D.'s at the boundaries and the diffusion potential within the membrane. Suppose the immobility of the anions is not absolute but only relative as compared with the mobility of the cations, KCl would gradually penetrate into the membrane to equal concentration with the outside solution on either side and no boundary potential would be established. In this case the diffusion P.D. within the membrane is the only P.D., amounting to See PDF for Equation but, V being practically = 0, it would result that See PDF for Equation So the definitive result is the same as in the former case. Now cancel the printed text as far as page 48...

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## Propagation of uncertainties and multimodality in the impact problem of two elastic bodies

Fonte: Elsevier
Publicador: Elsevier

Tipo: info:eu-repo/semantics/article; info:ar-repo/semantics/artículo; info:eu-repo/semantics/publishedVersion
Formato: application/pdf

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#Collision#Elastic bodies#Multimodality#Uncertainty#Mecánica Aplicada#Ingeniería Mecánica#INGENIERÍAS Y TECNOLOGÍAS

An uncertainty quantification study is carried out for the problem of the frontal collision of two elastic bodies. The time of contact and the resultant force function involved during the collision are the quantities of interest. If the initial conditions and the mechanical and geometrical properties were known, the response prediction would be deterministic. However, if the data contains any uncertainty, a stochastic approach becomes appropriate. Based on the Principle of Maximum Entropy (PME), and under certain restrictions on the parameter values, we derive the probability density function (PDF) for each of the stochastic parameters to construct a probabilistic model. Two cases are dealt with: one of a collision involving two spheres and another of a collision of two discs. In the first case, a parameter involving geometry and material properties is assumed stochastic. Since a functional relationship exists, the propagation of the uncertainty of the time of contact can be done symbolically. However, the interaction force function can only be computed from the solution of a nonlinear ordinary differential equation. Given the PDF of the parameter, the problem of uncertainty propagation is tackled using Monte Carlo simulations. The comparison of both approaches yields an excellent agreement. With respect to the collision of two discs...

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## Mercado de Trabalho: Conjuntura e Análise: n. 30, Maio. 2006

Fonte: Instituto de Pesquisa Econômica Aplicada (Ipea)
Publicador: Instituto de Pesquisa Econômica Aplicada (Ipea)

Tipo: Mercado de trabalho: conjuntura e análise

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O boletim Mercado de trabalho: conjuntura e análise tem periodicidade semestral e traz uma análise conjuntural do Mercado de trabalho, acompanhada de indicadores e seções temáticas que abordam tanto considerações mais técnicas como questões de cunho político-institucional.; n. 30, 40 p.; parte 1: Apresentação de conjuntura, arquivo pdf; parte 2: Análise do mercado de trabalho, arquivo pdf; parte 3: Nota Técnica: Desigualdade de rendimento do trabalho no Brasil no período pós-real, arquivo pdf; parte 4: Nota Técnica: O dilema do financiamento orçamentário das políticas públicas de emprego, arquivo pdf

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## Mercado de Trabalho: Conjuntura e Análise: n. 32, mar. 2007

Fonte: Instituto de Pesquisa Econômica Aplicada (Ipea)
Publicador: Instituto de Pesquisa Econômica Aplicada (Ipea)

Tipo: Mercado de trabalho: conjuntura e análise

Português

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O boletim Mercado de trabalho: conjuntura e análise tem periodicidade semestral e traz uma análise conjuntural do Mercado de trabalho, acompanhada de indicadores e seções temáticas que abordam tanto considerações mais técnicas como questões de cunho político-institucional.; n. 32, ca. 30 p.; parte 1: Apresentação da conjuntura, arquivo pdf; parte 2: Análise do mercado de trabalho, arquivo pdf; parte 3: Nota técnica: A evolução do mercado de trabalho metropolitano segundo a leitura da nova metodologia da pesquisa mensal de emprego no período de março de 2002 a dezembro de 2006, arquivo pdf; parte 4: Indicadores e previsões Ipea, em 6 arquivos pdf

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## On calibration of some distance scales in astrophysics

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

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We present a method for distance calibration without using standard fitting
procedures. Instead we use random resampling to reconstruct the probability
density function (PDF) of calibration data points in the fitting plane. The
resulting PDF is then used to estimate distance-related properties. The method
is applied to samples of radio surface brightness to diameter (\Sigma-D) data
for the Galactic supernova remnants (SNRs) and planetary nebulae (PNe), and
period-luminosity (PL) data for the Large Magellanic Cloud (LMC) fundamental
mode classical Cepheids. We argue that resulting density maps can provide more
accurate and more reliable calibrations than those obtained by standard linear
fitting procedures. For the selected sample of the Galactic SNRs, the presented
PDF method of distance calibration results in a smaller average distance
fractional error of up to $\approx 16$ percentage points. Similarly, the
fractional error is smaller for up to $\approx 8$ and $\approx 0.5$ percentage
points, for the samples of Galactic PNe and LMC Cepheids, respectively. In
addition, we provide a PDF-based calibration data for each of the samples.; Comment: 11 pages, 3 figures, corrected for mistakenly considering working
data as absolute instead of apparent magnitude...

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## Roughness distributions for 1/f^alpha signals

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

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The probability density function (PDF) of the roughness, i.e., of the
temporal variance, of 1/f^alpha noise signals is studied. Our starting point is
the generalization of the model of Gaussian, time-periodic, 1/f noise,
discussed in our recent Letter [T. Antal et al., PRL, vol. 87, 240601 (2001)],
to arbitrary power law. We investigate three main scaling regions,
distinguished by the scaling of the cumulants in terms of the microscopic scale
and the total length of the period. Various analytical representations of the
PDF allow for a precise numerical evaluation of the scaling function of the PDF
for any alpha. A simulation of the periodic process makes it possible to study
also non-periodic signals on short intervals embedded in the full period. We
find that for alpha=<1/2 the scaled PDF-s in both the periodic and the
non-periodic cases are Gaussian, but for alpha>1/2 they differ from the
Gaussian and from each other. Both deviations increase with growing alpha. That
conclusion, based on numerics, is reinforced by analytic results for alpha=2
and alpha->infinity. We suggest that our theoretical and numerical results open
a new perspective on the data analysis of 1/f^alpha processes.; Comment: 12 pages incl. 6 figures, with RevTex4...

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## What regulates the velocity distribution of interstellar clouds?

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 08/04/2002
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Kinetic energy stored in ISM bulk/turbulent motions is a crucial ingredient
to properly describe most properties of observed galaxies. By using Monte Carlo
simulations, we investigate how this energy is injected by supernovae and
dissipated via cloud collisions and derive the corresponding ISM velocity
probability distribution function (PDF). The functional form of the PDF for the
modulus of the velocity dispersion is $$p(v) \propto v^2
\exp[-(v/\sigma)^\beta].$$ The power-law index of the PDF depends only on the
value of the average cloud collision elasticity < \epsilon > as \beta =
2\exp(<\epsilon > -1). If \beta and the gas velocity dispersion \sigma are
known, the specific kinetic energy dissipated by collisions is found to be
\propto \sigma^2 \ln (2 / \beta)/(\beta-0.947); in steady state, this is equal
to the energy input from SNe. We predict that in a multiphase, low metallicity
(Z \approx 5 \times 10^{-3} Z_\odot) ISM the PDF should be close to a
Maxwellian (\beta = 2) with velocity dispersion \sigma \simgt 11$ km s\m; in
more metal rich systems (Z \simgt 5 \times 10^{-2} Z_\odot), instead, we expect
to observe almost exponential PDFs. This is in good agreement with a number of
observations that we review and might explain the different star formation
modes seen in dwarfs and spiral galaxies.; Comment: Accepted for publication of MNRAS. 10 pages including 7 figures

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## Gravitational lensing of the cosmic microwave background by nonlinear structures

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 08/07/2010
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Weak gravitational lensing changes the angular power spectra of the cosmic
microwave background (CMB) temperature and polarization in a characteristic way
containing valuable information for cosmological parameter estimation and weak
lensing reconstructions. So far, analytical expressions for the lensed CMB
power spectra assume the probability density function (PDF) of the lensing
excursion angle to be Gaussian. However, coherent light deflection by nonlinear
structures at low redshifts causes deviations from a pure Gaussian PDF. Working
in the flat-sky limit we develop a method for computing the lensed CMB power
spectra which takes these non-Gaussian features into account. Our method does
not assume any specific PDF but uses instead an expansion of the characteristic
function of the lensing excursion angle into its moments. Measuring these in
the CMB lensing deflection field obtained from the Millennium Simulation we
show that the change in the lensed power spectra is only at the 0.1% - 0.4%
level on very small scales (below 4 arcmin) and demonstrate that the assumption
of a Gaussian lensing excursion angle PDF is well applicable.; Comment: 9 pages, 2 figures, submitted to MNRAS

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## Finite-size effect and the components of multifractality in financial volatility

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 23/12/2009
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Many financial variables are found to exhibit multifractal nature, which is
usually attributed to the influence of temporal correlations and fat-tailedness
in the probability distribution (PDF). Based on the partition function approach
of multifractal analysis, we show that there is a marked finite-size effect in
the detection of multifractality, and the effective multifractality is the
apparent multifractality after removing the finite-size effect. We find that
the effective multifractality can be further decomposed into two components,
the PDF component and the nonlinearity component. Referring to the normal
distribution, we can determine the PDF component by comparing the effective
multifractality of the original time series and the surrogate data that have a
normal distribution and keep the same linear and nonlinear correlations as the
original data. We demonstrate our method by taking the daily volatility data of
Dow Jones Industrial Average from 26 May 1896 to 27 April 2007 as an example.
Extensive numerical experiments show that a time series exhibits effective
multifractality only if it possesses nonlinearity and the PDF has impact on the
effective multifractality only when the time series possesses nonlinearity. Our
method can also be applied to judge the presence of multifractality and
determine its components of multifractal time series in other complex systems.; Comment: 9 RevTex pages including 9 eps figures. Comments and suggestions are
warmly welcome

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## Tightening Constraints from the Lyman Alpha Forest with the Flux Probability Distribution Function

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 06/05/2005
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The analysis of the Lyman-alpha forest of absorption lines in quasar spectra
has emerged as a potentially powerful technique to constrain the linear matter
power spectrum. In most previous work, the amplitude of the ionizing background
was fixed by calibrating simulations to match the observed mean transmitted
flux in the Lyman-alpha forest. This procedure is undesirable in principle as
it requires the estimation of the unabsorbed quasar continuum level, a
difficult undertaking subject to various sources of systematic error and bias.
We suggest an alternative approach based on measuring the one-point probability
distribution function (pdf) of the fluctuations in the flux about the mean,
relative to the mean, i.e. the pdf of delta_f = (f - )/. This statistic,
while sensitive to the amplitude of the ionizing background, has the virtue
that its measurement does not require an estimate of the unabsorbed continuum
level. We present a measurement of the pdf of delta_f from seven Keck HIRES
spectra, spanning a redshift range of z = 2.2 - 4.4. To illustrate that our
method is useful, we compare our measurements of the pdf of delta_f, and
measurements of the flux power spectrum from Croft et al. (2002) at z = 2.72,
with cosmological simulations. From this comparison...

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## Statistical State Dynamics: a new perspective on turbulence in shear flow

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 29/12/2014
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Traditionally, single realizations of the turbulent state have been the
object of study in shear flow turbulence. When a statistical quantity was
needed it was obtained from a spatial, temporal or ensemble average of sample
realizations of the turbulence. However, there are important advantages to
studying the dynamics of the statistical state (the SSD) directly. In highly
chaotic systems statistical quantities are often the most useful and the
advantage of obtaining these statistics directly from a state variable is
obvious. Moreover, quantities such as the probability density function (pdf)
are often difficult to obtain accurately by sampling state trajectories even if
the pdf is stationary. In the event that the pdf is time dependent, solving
directly for the pdf as a state variable is the only alternative. However,
perhaps the greatest advantage of the SSD approach is conceptual: adopting this
perspective reveals directly the essential cooperative mechanisms among the
disparate spatial and temporal scales that underly the turbulent state. While
these cooperative mechanisms have distinct manifestation in the dynamics of
realizations of turbulence both these cooperative mechanisms and the phenomena
associated with them are not amenable to analysis directly through study of
realizations as they are through the study of the associated SSD. In this
review a selection of example problems in the turbulence of planetary and
laboratory flows is examined using recently developed SSD analysis methods in
order to illustrate the utility of this approach to the study of turbulence in
shear flow.; Comment: 25 pages...

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## CT14QED PDFs from Isolated Photon Production in Deep Inelastic Scattering

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 09/09/2015
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We describe the implementation of Quantum Electrodynamic (QED) evolution at
Leading Order (LO) along with Quantum Chromodynamic (QCD) evolution at
Next-to-Leading Order (NLO) in the CTEQ-TEA Global analysis package. The photon
Parton Distribution Function (PDF) is described by a two-parameter ansatz,
coming from radiation off the valence quarks, and based on the CT14 NLO PDFs.
Setting the two parameters equal, allows us to completely specify the photon
PDF in terms of the momentum fraction carried by the photon, $p_0^\gamma$, at
the initial scale $Q_0=1.295$ GeV. We obtain constraints on the photon PDF by
comparing with ZEUS data~\cite{Chekanov:2009dq} on the production of isolated
photons in deep inelastic scattering, $ep\rightarrow e\gamma+X$. For this
comparison we present a new perturbative calculation of the process that
consistently combines the photon-initiated contribution with the
quark-initiated contribution. Comparison with the data allows us to put a
constraint at the 90% confidence level of $p_0^\gamma\lesssim0.14\%$ for the
photon PDF at the initial scale of $Q_0=1.295$ GeV in the one-parameter
radiative ansatz. The resulting CT14QED PDFs will be made available to the
public.; Comment: 26 pages, 13 figures

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## Universal compression of Gaussian sources with unknown parameters

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 16/10/2014
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For a collection of distributions over a countable support set, the worst
case universal compression formulation by Shtarkov attempts to assign a
universal distribution over the support set. The formulation aims to ensure
that the universal distribution does not underestimate the probability of any
element in the support set relative to distributions in the collection. When
the alphabet is uncountable and we have a collection $\cal P$ of Lebesgue
continuous measures instead, we ask if there is a corresponding universal
probability density function (pdf) that does not underestimate the value of the
density function at any point in the support relative to pdfs in $\cal P$.
Analogous to the worst case redundancy of a collection of distributions over
a countable alphabet, we define the \textit{attenuation} of a class to be $A$
when the worst case optimal universal pdf at any point $x$ in the support is
always at least the value any pdf in the collection $\cal P$ assigns to $x$
divided by $A$. We analyze the attenuation of the worst optimal universal pdf
over length-$n$ samples generated \textit{i.i.d.} from a Gaussian distribution
whose mean can be anywhere between $-\alpha/2$ to $\alpha/2$ and variance
between $\sigma_m^2$ and $\sigma_M^2$. We show that this attenuation is finite...

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## Toward First-Principle Simulations of Galaxy Formation: II. Shock-Induced Starburst at a Collision Interface During the First Encounter of Interacting Galaxies

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

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We investigated the evolution of interacting disk galaxies using
high-resolution $N$-body/SPH simulations, taking into account the multiphase
nature of the interstellar medium (ISM). In our high-resolution simulations, a
large-scale starburst occurred naturally at the collision interface between two
gas disks at the first encounter, resulting in the formation of star clusters.
This is consistent with observations of interacting galaxies. The probability
distribution function (PDF) of gas density showed clear change during the
galaxy-galaxy encounter. The compression of gas at the collision interface
between the gas disks first appears as an excess at $n_{\rm H} \sim 10{\rm
cm^{-3}}$ in the PDF, and then the excess moves to higher densities ($n_{\rm H}
\gtrsim 100{\rm cm^{-3}}$) in a few times $10^7$ years where starburst takes
place. After the starburst, the PDF goes back to the quasi-steady state. These
results give a simple picture of starburst phenomena in galaxy-galaxy
encounters.; Comment: 6 pages, 6 figures, accepted to PASJ. For high resolution figures,
see http://www.cfca.nao.ac.jp/~saitoh/Papers/2009/Saitoh+2009a.pdf

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## A collaborative theoretical and experimental study of the structure and electronic excitation spectrum of the BAr and B(Ar)2 complexes

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 23/01/1997
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We report the investigation of the 3s <- 2p transition in the BAr2 cluster.
In a supersonic expansion of B atoms entrained in Ar, at high beam source
backing pressures we observe several features in the fluorescence excitation
spectrum which cannot be assigned to the BAr diatom. Using BAr(X, B) potential
energy curves which reproduce our experimental observations on this molecule
and an Ar-Ar interaction potential, we employ a pairwise additive model, along
with variational and diffusion Monte-Carlo treatments of the nuclear motion, to
determine the lowest vibrational state of the BAr2 cluster. A subsequent
simulation of the fluorescence excitation spectrum reproduces nearly
quantitatively the strongest feature in our experimental spectrum not
assignable to BAr. Because of the barrier in the BAr(B 2Sigma+) potential
energy curve, the 3s <- 2p transition in the BAr2 cluster is predicted to have
an asymmetric profile, as is found experimentally.; Comment: a pdf file (5 kB) containing the abstract can be retrieved as
ftp://mha-ibm2.umd.edu/pub/publications/BAr2.abs.pdf a pdf file (325 kB)
containing the entire manuscript can be retrieved as
ftp://mha-ibm2.umd.edu/pub/publications/BAr2.ms.pdf To appear in J. Chem.
Phys. 106 (1997) 8 April issue.

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## A quasi-Gaussian approximation for the probability distribution of correlation functions

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Português

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Context. Whenever correlation functions are used for inference about
cosmological parameters in the context of a Bayesian analysis, the likelihood
function of correlation functions needs to be known. Usually, it is
approximated as a multivariate Gaussian, though this is not necessarily a good
approximation.
Aims. We show how to calculate a better approximation for the probability
distribution of correlation functions, which we call "quasi-Gaussian".
Methods. Using the exact univariate PDF as well as constraints on correlation
functions previously derived, we transform the correlation functions to an
unconstrained variable for which the Gaussian approximation is well justified.
From this Gaussian in the transformed space, we obtain the quasi-Gaussian PDF.
The two approximations for the probability distributions are compared to the
"true" distribution as obtained from simulations. Additionally, we test how the
new approximation performs when used as likelihood in a toy-model Bayesian
analysis.
Results. The quasi-Gaussian PDF agrees very well with the PDF obtained from
simulations; in particular, it provides a significantly better description than
a straightforward copula approach. In a simple toy-model likelihood analysis,
it yields noticeably different results than the Gaussian likelihood...

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## Quantum magnetism in two dimensions: From semi-classical Neel order to magnetic disorder

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 23/12/2004
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This is a review of ground-state features of the s=1/2 Heisenberg
antiferromagnet on two-dimensional lattices. A central issue is the interplay
of lattice topology (e.g. coordination number, non-equivalent nearest-neighbor
bonds, geometric frustration) and quantum fluctuations and their impact on
possible long-range order. This article presents a unified summary of all 11
two-dimensional uniform Archimedean lattices which include e.g. the square,
triangular and kagome lattice. We find that the ground state of the spin-1/2
Heisenberg antiferromagnet is likely to be semi-classically ordered in most
cases. However, the interplay of geometric frustration and quantum fluctuations
gives rise to a quantum paramagnetic ground state without semi-classical
long-range order on two lattices which are precisely those among the 11 uniform
Archimedean lattices with a highly degenerate ground state in the classical
limit. The first one is the famous kagome lattice where many low-lying singlet
excitations are known to arise in the spin gap. The second lattice is called
star lattice and has a clear gap to all excitations.
Modification of certain bonds leads to quantum phase transitions which are
also discussed briefly. Furthermore, we discuss the magnetization process of
the Heisenberg antiferromagnet on the 11 Archimedean lattices...

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## Nonparametric tests of structure for high angular resolution diffusion imaging in Q-space

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

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High angular resolution diffusion imaging data is the observed characteristic
function for the local diffusion of water molecules in tissue. This data is
used to infer structural information in brain imaging. Nonparametric scalar
measures are proposed to summarize such data, and to locally characterize
spatial features of the diffusion probability density function (PDF), relying
on the geometry of the characteristic function. Summary statistics are defined
so that their distributions are, to first-order, both independent of nuisance
parameters and also analytically tractable. The dominant direction of the
diffusion at a spatial location (voxel) is determined, and a new set of axes
are introduced in Fourier space. Variation quantified in these axes determines
the local spatial properties of the diffusion density. Nonparametric hypothesis
tests for determining whether the diffusion is unimodal, isotropic or
multi-modal are proposed. More subtle characteristics of white-matter
microstructure, such as the degree of anisotropy of the PDF and symmetry
compared with a variety of asymmetric PDF alternatives, may be ascertained
directly in the Fourier domain without parametric assumptions on the form of
the diffusion PDF. We simulate a set of diffusion processes and characterize
their local properties using the newly introduced summaries. We show how
complex white-matter structures across multiple voxels exhibit clear
ellipsoidal and asymmetric structure in simulation...

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## Reconstruction of the One-point Distribution of Convergence from Weak Lensing by Large-scale Structure

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Português

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Weak lensing measurements are starting to provide statistical maps of the
distribution of matter in the universe that are increasingly precise and
complementary to cosmic microwave background maps. The probability distribution
(PDF) provides a powerful tool to test non-Gausian features in the convergence
field and to discriminate the different cosmological models. In this letter, we
present a new PDF space Wiener filter approach to reconstruct the probability
density function of the convergence from the noisy convergence field. We find
that for parameters comparable to the CFHT legacy survey, the averaged PDF of
the convergence in a 3 degree field can be reconstructed with an uncertainty of
about 10%, even though the pointwise PDF is noise dominated.; Comment: 21 pages, 8 figures, accepted for publication in ApJ, added some
discussions

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## The Arecibo Galaxy Environments Survey - Description and Early Results

Fonte: Universidade Cornell
Publicador: Universidade Cornell

Tipo: Artigo de Revista Científica

Publicado em 20/10/2006
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The Arecibo Galaxy Environments Survey (AGES) is a 2000-hour neutral hydrogen
(HI) survey using the new Arecibo L-band Feed Array (ALFA) multibeam instrument
at Arecibo Observatory. It will cover 200 square degrees of sky, sampling a
range of environments from the Local Void through to the Virgo Cluster with
higher sensitivity, spatial resolution and velocity resolution than previous
neutral hydrogen surveys.; Comment: IAU Symposium 235 - Galaxy Evolution across the Hubble Time. 3 pages
(only 1 st to appear in printed proceedings), 3 figures. Uses iaus.cls. Full
resolution PDF is available from
http://www2.naic.edu/alfa/ealfa/AGES-IAUS235-Minchin.pdf and a PDF of the
poster is available from http://www2.naic.edu/alfa/ealfa/AGES-IAU-Minchin.pdf

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