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Contributions to the nonlinear integrated Sachs-Wolfe effect: Birkinshaw-Gull effect and gravitational self-energy density  [PDF]
Philipp Merkel,Bjoern Malte Schaefer
Physics , 2012, DOI: 10.1093/mnras/stt341
Abstract: In this paper, we recompute contributions to the spectrum of the nonlinear integrated Sachs-Wolfe (iSW)/Rees-Sciama effect in a dark energy cosmology. Focusing on the moderate nonlinear regime, all dynamical fields involved are derived from the density contrast in Eulerian perturbation theory. Shape and amplitude of the resulting angular power spectrum are similar to that derived in previous work. With our purely analytical approach we identify two distinct contributions to the signal of the nonlinear iSW-effect: the change of the gravitational self-energy density of the large scale structure with (conformal) time and gravitational lenses moving with the large scale matter stream. In the latter we recover the Birkinshaw-Gull effect. As the nonlinear iSW-effect itself is inherently hard to detect, observational discrimination between its individual contributions is almost excluded. Our analysis, however, yields valuable insights into the theory of the nonlinear iSW-effect as a post-Newtonian relativistic effect on propagating photons.
On the sources of the late integrated Sachs-Wolfe effect  [PDF]
Marius J. Fullana,Diego Saez
Physics , 2000, DOI: 10.1016/S1384-1076(00)00016-6
Abstract: In some scenarios, the peculiar gravitational potential of linear and mildly nonlinear structures depends on time and, as a result of this dependence, a late integrated Sachs-Wolfe effect appears. Here, an appropriate formalism is used which allows us to improve on the analysis of the spatial scales and locations of the main cosmological inhomogeneities producing this effect. The study is performed in the framework of the currently preferred flat model with cosmological constant, and it is also developed in an open model for comparisons. Results from this analysis are used to discuss the contribution of Great Attractor-like objects, voids, and other structures to the CMB anisotropy.
Mapping the Integrated Sachs-Wolfe Effect  [PDF]
A. Manzotti,S. Dodelson
Physics , 2014, DOI: 10.1103/PhysRevD.90.123009
Abstract: On large scales, the anisotropies in the cosmic microwave background (CMB) reflect not only the primordial field but also the energy gain when photons traverse decaying gravitational potentials of large scales structure, the Integrated Sachs-Wolfe (ISW) effect. Decomposing the anisotropy signal into a primordial piece and an ISW component is more urgent than ever as cosmologists strive to understand the Universe on the largest of scales. Here we present a likelihood technique for extracting the ISW signal from measurements of the CMB, the distribution of galaxies, and maps of gravitational lensing. We test this technique first to simulated data and then we apply it to the combination of temperature anisotropies, the lensing map made by the Planck satellite, and the NVSS galaxy survey. We also show projections for upcoming surveys.
Integrated Sachs Wolfe Effect and Rees Sciama Effect  [PDF]
Atsushi J. Nishizawa
Physics , 2014, DOI: 10.1093/ptep/ptu062
Abstract: It has been around fifty years since R. K. Sachs and A. M. Wolfe predicted the existence of anisotropy in the Cosmic Microwave Background (CMB) and ten years since the integrated Sachs Wolfe effect (ISW) was first detected observationally. The ISW effect provides us with a unique probe of the accelerating expansion of the Universe. The cross-correlation between the large-scale structure and CMB has been the most promising way to extract the ISW effect from the data. In this article, we review the physics of the ISW effect and summarize recent observational results and interpretations.
The Small Scale Integrated Sachs-Wolfe Effect  [PDF]
Wayne Hu,Naoshi Sugiyama
Physics , 1993, DOI: 10.1103/PhysRevD.50.627
Abstract: The integrated Sachs-Wolfe effect (ISW) can be an important factor in the generation of Cosmic Microwave Background anisotropies on all scales, especially in a reionized curvature or lambda dominated universe. We present an analytic treatment of the ISW effect, which is analogous to thick last scattering surface techniques for the Doppler effect, that compares quite well with the full numerical calculations. The power spectrum of temperature fluctuations due to the small scale ISW effect has wave number dependence k^{-5} times that of the matter power spectrum.
The gravitational light shift and the Sachs-Wolfe effect  [PDF]
Cesar Merlin,Marcelo Salgado
Physics , 2011, DOI: 10.1007/s10714-011-1193-7
Abstract: Using a 3+1 decomposition of spacetime, we derive a new formula to compute the gravitational light shifts as measured by two observers which are normal to the spacelike hypersurfaces defining the foliation. This formula is quite general and is also independent of the existence of Killing fields. Known examples are considered to illustrate the usefulness of the formula. In particular, we focus on the Sachs-Wolfe effect that arises in a perturbed Friedman-Robertson-Walker cosmology.
Non-linear Integrated Sachs-Wolfe Effect  [PDF]
Asantha Cooray
Physics , 2001, DOI: 10.1103/PhysRevD.65.083518
Abstract: We discuss the non-linear extension to the integrated Sachs-Wolfe effect (ISW) resulting from the divergence of the large scale structure momentum density field. The non-linear ISW effect leads to an increase in the total ISW contribution by roughly two orders of magnitude at l ~ 1000. This increase, however, is still below the cosmic variance limit of the primary anisotropies; at further small angular scales, secondary effects such as gravitational lensing and the kinetic Sunyaev-Zel'dovich (SZ) effect dominates the non-linear ISW power spectrum. We show this second-order non-linear ISW contribution is effectively same as the contribution previously described as a lensing effect due to the transverse motion of gravitational lenses and well known as the Kaiser-Stebbins effect under the context of cosmic strings. Due to geometrical considerations, there is no significant three point correlation function, or a bispectrum, between the linear ISW effects and its non-linear extension. The non-linear ISW contribution can be potentially used as a probe of the transverse velocity of dark matter halos such as galaxy clusters. Due to the small contribution to temperature fluctuations, of order few tenths of micro Kelvin, however, extrating useful measurements on velocities will be challenging.
Integrated Sachs-Wolfe tomography with orthogonal polynomials  [PDF]
Gero Jürgens,Bjoern Malte Sch?fer
Physics , 2012, DOI: 10.1111/j.1365-2966.2012.21125.x
Abstract: Topic of this article are tomographic measurements of the integrated Sachs-Wolfe effect with specifically designed, orthogonal polynomials which project out statistically independent modes of the galaxy distribution. The polynomials are contructed using the Gram-Schmidt orthogonalisation method. To quantify the power of the iSW-effect in contraining cosmological parameters we perfom a combined Fisher matrix analysis for the iSW-, galaxy- and cross-spectra for wCDM cosmologies using the survey characteristics of PLANCK and EUCLID. The signal to noise ratio has also been studied for other contemporary galaxy surveys, such as SDSS, NVSS and 2MASS. For the cross-spectra our tomographic method provides a 16% increase in the signal to noise ratio and an improvement of up to 30% in conditional errors on parameters. Including all spectra, the marginalised errors approach an inverse square-root dependence with increasing cumulative polynomial order which underlines the statistical independence of the weighted signal spectra.
The significance of the integrated Sachs-Wolfe effect revisited  [PDF]
Tommaso Giannantonio,Robert Crittenden,Robert Nichol,Ashley J. Ross
Physics , 2012, DOI: 10.1111/j.1365-2966.2012.21896.x
Abstract: 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.
A new approach to the Sachs-Wolfe effect  [PDF]
J. Tito Mendonca,Robert Bingham,Charles H. -T. Wang
Physics , 2005, DOI: 10.1088/0264-9381/25/9/095015
Abstract: We present a new approach to the Sachs-Wolfe effect, which is based on the dynamics of photons in a space and time varying gravitational field. We consider the influence of plasma dispersion effects on photon propagation, and establish the limits of validity of the usual results of the standard cosmological approach, for the large scale temperature anisotropies of the cosmic microwave background. New dynamical contributions to the integrated Sachs-Wolfe effect are also discussed.
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