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Related papers: Note on Redshift Distortion in Fourier Space

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We present a study of the 21-cm signal bispectrum (which quantifies the non-Gaussianity in the signal) from the Cosmic Dawn (CD). For our analysis, we have simulated the 21-cm signal using radiative transfer code GRIZZLY, while considering…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-02 Mohd Kamran , Raghunath Ghara , Suman Majumdar , Rajesh Mondal , Garrelt Mellema , Somnath Bharadwaj , Jonathan R. Pritchard , Ilian T. Iliev

The nonlinear perturbation theory of gravitational instability is extended to include effects of both biasing and redshift-space distortions, which are inevitable in predicting observable quantities in galaxy surveys. The precise…

Astrophysics · Physics 2014-11-18 Takahiko Matsubara

We study the power spectrum dipole of an N-body simulation which includes relativistic effects through ray-tracing and covers the low redshift Universe up to $z_{\rm max} = 0.465$ (RayGalGroup simulation). We model relativistic corrections…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-05 Florian Beutler , Enea Di Dio

The cosmological fluid equations are used to study the nonlinear mode coupling of density fluctuations. We find that for realistic cosmological spectra there is a significant contribution to the nonlinear evolution on scales of interest to…

Astrophysics · Physics 2007-05-23 Bhuvnesh Jain , Edmund Bertschinger

We systematically study the effects of varying the starting redshift z_i for cosmological simulations in the highly non-linear regime. Our primary focus lies with the (individual) properties of dark matter halos -- namely the mass, spin,…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Alexander Knebe , Christian Wagner , Steffen Knollmann , Tobias Diekershoff , Fabian Krause

In the pursuit of primordial non-Gaussianities, we hope to access smaller scales across larger comoving volumes. At low redshift, the search for primordial non-Gaussianities is hindered by gravitational collapse, to which we often associate…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-08 Thomas Flöss , Matteo Biagetti , P. Daniel Meerburg

We study constraints on primordial mode-coupling from the power spectrum, squeezed-limit bispectrum and collapsed trispectrum of matter and halos. We describe these statistics in terms of long-wavelength $2$-point functions involving the…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-20 Roland de Putter

Redshift-space distortions in galaxy surveys happen along the radial direction, breaking statistical translation invariance. We construct estimators for radial distortions that, using only Fast Fourier Transforms (FFTs) of the overdensity…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 Roman Scoccimarro

The observed two-point correlation functions of galaxies in redshift space become anisotropic due to the geometry of the universe as well as due to the presence of the peculiar velocity field. On the basis of linear perturbation theory, we…

Astrophysics · Physics 2009-10-30 Takahiro T. Nakamura , Takahiko Matsubara , Yasushi Suto

In paper I of this series we discuss how magnification bias distorts the 3D correlation function by enhancing the observed correlation in the line-of-sight (LOS) orientation, especially on large scales. This lensing anisotropy is…

Astrophysics · Physics 2008-11-26 Lam Hui , Enrique Gaztanaga , Marilena LoVerde

An acoustic oscillation of the primeval photon-baryon fluid around the decoupling time imprints a characteristic scale in the galaxy distribution today, known as the baryon acoustic oscillation (BAO) scale. Several on-going and/or future…

Redshift space distortion (RSD) observed in galaxy redshift surveys is a powerful tool to test gravity theories on cosmological scales, but the systematic uncertainties must carefully be examined for future surveys with large statistics.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Takashi Ishikawa , Tomonori Totani , Takahiro Nishimichi , Ryuichi Takahashi , Naoki Yoshida , Motonari Tonegawa

We present a power spectrum analysis of the final 2dF Galaxy Redshift Survey, employing a direct Fourier method. The sample used comprises 221,414 galaxies with measured redshifts. We investigate in detail the modelling of the sample…

abridged] A method to rapidly estimate the Fourier power spectrum of a point distribution is presented. This method relies on a Taylor expansion of the trigonometric functions. It yields the Fourier modes from a number of FFTs, which is…

Astrophysics · Physics 2009-11-13 Stephane Colombi , Andrew H. Jaffe , Dmitri Novikov , Christophe Pichon

The cosmological redshift drift promises to be the first observable directly measuring the evolution of the cosmic expansion rate and should be detectable with upcoming surveys by the Square Kilometre Array and the Extremely Large…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Alexander Oestreicher , Chris Clarkson , Julian Adamek , Sofie Marie Koksbang

Inflationary models predict a correlation between primordial density perturbations (scalar metric perturbations) and gravitational waves (tensor metric perturbations) in the form of a scalar-scalar-tensor three-point correlation, or…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-09 Liang Dai , Donghui Jeong , Marc Kamionkowski

Neutral hydrogen (HI) will soon be the dark matter tracer observed over the largest volumes of Universe thanks to the 21 cm intensity mapping technique. To unveil cosmological information it is indispensable to understand the HI…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-06 Aurélie Pénin , Obinna Umeh , Mario Santos

We perform a systematic analysis of the effects of photometric redshift uncertainties on weak lensing tomography. We describe the photo-z distribution with a bias and Gaussian scatter that are allowed to vary arbitrarily between intervals…

Astrophysics · Physics 2009-11-13 Zhaoming Ma , Wayne Hu , Dragan Huterer

Theoretical modeling of the redshift-space power spectrum of galaxies is crucially important to correctly extract cosmological information from redshift surveys. The task is complicated by the nonlinear biasing and redshift space distortion…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-26 Teppei Okumura , Nick Hand , Uros Seljak , Zvonimir Vlah , Vincent Desjacques

Measurements of the cosmic redshift drift - the change in redshift of a source over time - will enable independent detection of cosmological expansion thanks to the immense precision soon reached by new facilities such as the Square…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-16 Sofie Marie Koksbang , Asta Heinesen , Hayley J. Macpherson