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We perform for the first time a joint analysis of the monopole and quadrupoles for power spectrum, bispectrum and integrated trispectrum (i-trispectrum) from the redshift space matter field in N-body simulations. With a full Markov Chain…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-09 Davide Gualdi , Hector Gil-Marin , Licia Verde

The observed 21-cm signal from the epoch of reionization will be distorted along the line-of-sight by the peculiar velocities of matter particles. These redshift-space distortions will affect the contrast in the signal and will also make it…

We present a new method for calculating CMB anisotropies in a non-flat Friedmann universe, relying on a very stable algorithm for the calculation of hyperspherical Bessel functions, that can be pushed to arbitrary precision levels. We also…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Julien Lesgourgues , Thomas Tram

We consider the acoustic-n-point (AnP) problem, which estimates the pose of a 2D forward-looking sonar (FLS) according to n 3D-2D point correspondences. We explore the nature of the measured partial spherical coordinates and reveal their…

The cosmic radio dipole is an anisotropy in the number counts of radio sources, analogous to the dipole seen in the cosmic microwave background (CMB). Measurements of source counts of large radio surveys have shown that though the radio…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-05 J. D. Wagenveld , H-R. Klöckner , D. J. Schwarz

Measuring the three-point correlators of the Cosmic Microwave Background (CMB) anisotropies could help to get a handle on the level of non-Gaussianity present in the observational datasets and therefore would strongly constrain models of…

Astrophysics · Physics 2008-11-26 Alejandro Gangui , Jerome Martin

The bispectrum, the three-point function of density fluctuations in Fourier space, is the lowest order statistic that carries information about the spatial coherence of large-scale structures. For Gaussian initial conditions, when the…

We develop an analytic theory for the redshift space bispectrum of dark matter, haloes and galaxies. This is done within the context of the halo model of structure formation, as this allows for the self-consistent inclusion of linear and…

Astrophysics · Physics 2008-12-18 Robert E. Smith , Ravi K. Sheth , Roman Scoccimarro

We present GEO-FPT (Geometric Fitted Perturbation Theory), a new model for the galaxy bispectrum anisotropic signal in redshift space, with functional form rooted in perturbation theory. It also models the dependence of the bispectrum with…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-20 Sergi Novell-Masot , Davide Gualdi , Héctor Gil-Marín , Licia Verde

We present two estimators to quantify the angular power spectrum of the sky signal directly from the visibilities measured in radio interferometric observations. This is relevant for both the foregrounds and the cosmological 21-cm signal…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-11 Samir Choudhuri , Somnath Bharadwaj , Abhik Ghosh , SK. Saiyad Ali

The local void model has recently attracted considerable attention because it can explain the apparent accelerated expansion of the present universe without introducing dark energy. However, in order to justify this model as an alternative…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-27 Hideo Kodama , Keiki Saito , Akihiro Ishibashi

We present an efficient method to compute CMB anisotropies in non-flat universes. First we derive the Boltzmann equation for cosmic microwave background temperature and polarization fluctuations produced by scalar perturbations in a general…

Astrophysics · Physics 2009-06-16 Matias Zaldarriaga , Uros Seljak , Edmund Bertschinger

To probe cosmological fields beyond the Gaussian level, three-point statistics can be used, all of which are related to the bispectrum. Hence, measurements of CMB anisotropies, galaxy clustering, and weak gravitational lensing alike have to…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-03 B. Joachimi , X. Shi , P. Schneider

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

We describe a general expansion of spherical (full-sky) bispectra into a set of orthogonal modes. For squeezed shapes, the basis separates physically-distinct signals and is dominated by the lowest moments. In terms of reduced bispectra, we…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-23 Julien Carron , Antony Lewis

We consider two-dimensional chiral, first-order conformal field theories governing maps from the Riemann sphere to the projective light cone inside Minkowski space -- the natural setting for describing conformal field theories in two fewer…

High Energy Physics - Theory · Physics 2017-09-13 Tim Adamo , Ricardo Monteiro , Miguel F. Paulos

We consider the benefits of measuring cosmic statistical anisotropy from redshift-space correlators of the galaxy number density fluctuation and the peculiar velocity field without adopting the plane-parallel (PP) approximation. Since the…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-17 Maresuke Shiraishi , Teppei Okumura , Kazuyuki Akitsu

A near-future detection of the 21cm signal from the epoch of reionization will provide unique opportunities to probe the underlying cosmology, provided that such cosmological information can be extracted with precision. To this end, we…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-28 Wenzer Qin , Katelin Schutz , Aaron Smith , Enrico Garaldi , Rahul Kannan , Tracy R. Slatyer , Mark Vogelsberger

Current and upcoming large-scale structure surveys are pushing toward increasingly wide angular coverage, where wide-angle effects (arising from the varying line of sight across the curved sky) become critical for accurate modeling of the…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-28 Robin Y. Wen , Henry S. Grasshorn Gebhardt , Chen Heinrich , Olivier Doré

We present the first application of the isosceles bispectrum to MCMC parameter inference from the cosmic 21-cm signal. We extend the MCMC sampler 21cmMC to use the fast bispectrum code, BiFFT, when computing the likelihood. We create mock…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-19 Catherine A. Watkinson , Bradley Greig , Andrei Mesinger
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