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We investigate the effects of finite sky coverage on the spectral resolution $\Delta\ell$ in the estimation of the CMBR angular power spectrum $C^{\ell}$. A method is developed for obtaining quasi-independent estimates of the power…

Astrophysics · Physics 2015-06-24 M. P. Hobson , Joao Magueijo

We argue that the acoustic damping of the matter power spectrum is not a generic feature of the kinetic decoupling of dark matter, but even the enhancement can be realized depending on the nature of the kinetic decoupling when compared to…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-14 Ayuki Kamada , Tomo Takahashi

We compute the angular power spectrum of the $B$-modes of the weak-lensing shear in a spatially anisotropic spacetime. We find that there must also exist off-diagonal correlations between the $E$-modes, $B$-modes, and convergence that allow…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-13 Thiago S. Pereira , Cyril Pitrou , Jean-Philippe Uzan

We examine the influence of percent-level dark energy corrections to the nonlinear matter power spectrum on constraints of the dark energy equation of state from future weak lensing probes. We explicitly show that a poor approximation (off…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-28 Shahab Joudaki , Asantha Cooray , Daniel E. Holz

Matter inhomogeneities along the line of sight deflect the cosmic microwave background (CMB) photons originating at the last scattering surface at redshift $z \sim 1100$. These distortions modify the pattern of CMB polarization. We identify…

Astrophysics · Physics 2009-10-31 Jacek Guzik , Uros Seljak , Matias Zaldarriaga

Noticeable deviations from the prediction of the fiducial LCDM cosmology are found in the angular power spectrum of the CMB. Besides large-angle anomalies, the WMAP 1st year data revealed a dip in the power spectrum at l \sim 200, which…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-12 Amanda Yoho , Francesc Ferrer , Glenn D. Starkman

We review recent work aimed at showing how global topological defects influence the shape of the angular power spectrum of the CMB radiation on small scales. While Sachs-Wolfe fluctuations give the dominant contribution on angular scales…

Astrophysics · Physics 2007-05-23 Alejandro Gangui , Ruth Durrer , Mairi Sakellariadou

Modelling of the weak lensing of the CMB will be crucial to obtain correct cosmological parameter constraints from forthcoming precision CMB anisotropy observations. The lensing affects the power spectrum as well as inducing…

Astrophysics · Physics 2010-11-17 Antony Lewis

Speckle photography can be used to monitor deformations of solid surfaces. The measuring characteristics, such as range or lateral resolution depend heavily on the optical recording and illumination set-up. This paper shows how, by the…

Optics · Physics 2014-01-30 Jose M. Diazdelacruz

We present a method for measuring CMB polarization power spectra given incomplete sky coverage and test it with simulated examples such as Boomerang 2001 and MAP. By augmenting the quadratic estimator method with an additional step, we find…

Astrophysics · Physics 2009-10-07 Max Tegmark , Angelica de Oliveira-Costa

In this paper we investigate the impact that realistic scale-dependence systematic effects may have on cosmic shear tomography. We model spatially varying residual ellipticity and size variations in weak lensing measurements and propagate…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-09 T. D. Kitching , A. N. Taylor , M. Cropper , H. Hoekstra , R. K. E. Hood , R. Massey , S. Niemi

Exciting experiments in the field of atom and molecule optics have lately drawn much attention to the effects involved in the coherent diffraction of particle beams. We review the influence of the finite size of the particles and of their…

Quantum Physics · Physics 2007-05-23 Martin Stoll , Thorsten Koehler , Gerhard C. Hegerfeldt

One of the main goals of modern observational cosmology is to map the large scale structure of the Universe. A potentially powerful approach for doing this would be to exploit three-dimensional spectral maps, i.e. the specific intensity of…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-18 Roland de Putter , Gilbert P. Holder , Tzu-Ching Chang , Olivier Dore

[Abridged] A sharp cut-off in the primordial scalar power spectrum on large scales has been known to improve the fit to the cosmic microwave background (CMB) data when compared to the more standard, nearly scale invariant power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-11 H. V. Ragavendra , Debika Chowdhury , L. Sriramkumar

The statistics of peak counts in reconstructed shear maps contain information beyond the power spectrum, and can improve cosmological constraints from measurements of the power spectrum alone if systematic errors can be controlled. We study…

The matter power spectrum has been strongly constrained by astronomical measurements at large scales, but only weakly at small scales. Compared with the standard scenario, the deviation of the matter power spectrum at small scales has…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-12 Yupeng Yang , Xiujuan Li , Gang Li

The properties of a dissipative system depend on the spectral density of the coupling to the environment. Mostly, the dependence on the low-frequency behavior is in the focus of interest. However, in order to avoid divergencies, it is also…

Statistical Mechanics · Physics 2015-10-09 Benjamin Spreng , Gert-Ludwig Ingold , Ulrich Weiss

Observations of the large-scale structure (LSS) implicitly assume an ideal FLRW observer with the ambient structure having no influence on the observer. However, due to correlations in the LSS, cosmological observables are dependent on the…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-05 Robert Reischke , Björn malte Schäfer , Krzysztof Bolejko , Geraint F. Lewis , Max Lautsch

This article details the computation of the two-point correlators of the convergence, $E$- and $B$-modes of the cosmic shear induced by the weak-lensing by large scale structure assuming that the background spacetime is spatially…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-13 Cyril Pitrou , Thiago S. Pereira , Jean-Philippe Uzan

We study the effects of negative spatial curvature on the statistics of inhomogeneities in open cosmological models. In particular we examine the suppression of large-separation correlations in density and gravitational potential…

Astrophysics · Physics 2009-10-22 Albert Stebbins , R. R. Caldwell