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We study signatures in the Cosmic Microwave Background (CMB) induced by the presence of strong spatial curvature prior to the epoch of inflation which generated our present universe. If inflation does not last sufficiently long to drive the…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-02 Tim Clunan , David Seery

Deviations from the blackbody spectral energy distribution of the CMB are a precise probe of physical processes active both in the early universe (such as those connected to particle decays and inflation) and at later times (e.g.…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-05 Federico Bianchini , Giulio Fabbian

We present a method, based on the correlation function of excursion sets above a given threshold, to test the Gaussianity of the CMB temperature fluctuations in the sky. In particular, this method can be applied to discriminate between…

Astrophysics · Physics 2009-10-30 R. B. Barreiro , J. L. Sanz , E. Martinez-Gonzalez , J. Silk

Non-trivial spatial topology of the Universe can imprint potentially observable signatures on the cosmic microwave background (CMB). In this study, we investigate how deviations from the standard nearly-scale-free primordial power spectrum…

CMB full-sky temperature data show a hemispherical asymmetry in power nearly aligned with the Ecliptic. In real space, this anomaly can be quantified by the temperature variance in the northern and southern Ecliptic hemispheres, with the…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Marcio O'Dwyer , Craig J. Copi , Johanna M. Nagy , C. Barth Netterfield , John Ruhl , Glenn D. Starkman

In Luparello et al. 2023, a new and hitherto unknown CMB foreground was detected. A systematic decrease in Cosmic Microwave Background (CMB) temperatures around nearby large spiral galaxies points to an unknown interaction with CMB photons…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-19 Frode K. Hansen , Ezequiel F. Boero , Heliana E. Luparello , Diego Garcia Lambas

Although cosmological observations suggest that the fluctuations of seed fields are almost Gaussian, the possibility of a small deviation of their fields from Gaussianity is widely discussed. Theoretically, there exist numerous inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Maresuke Shiraishi

We analyze statistical properties of the separate multipole moments of the CMB temperature maps and find that the distribution tails are slightly non-Gaussian. Moreover, the deviation from Gaussianity peaks sharply at around $l\sim45\pm10$.…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-01 Vitaly Vanchurin

We present a phenomenological investigation of non-Gaussian effects that could be seen on CMB temperature maps. Explicit expressions for the temperature correlation functions are given for different types of primordial mode couplings. We…

Astrophysics · Physics 2011-01-20 T. Brunier , F. Bernardeau

We present a study of the effect of component separation on the recovered cosmic microwave background (CMB) temperature distribution, considering Gaussian and non-Gaussian input CMB maps. First, we extract the CMB component from simulated…

Astrophysics · Physics 2009-11-10 R. B. Barreiro , E. Martinez-Gonzalez , P. Vielva , M. P. Hobson

A convincing detection of primordial non-Gaussianity in the cosmic background radiation (CMB) is essential to probe the physics of the early universe. Since a single statistical estimator can hardly be suitable to detect the various…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-11 W. Cardona , A Bernui , M. J. Reboucas

We explore a systematic approach to the analysis of primordial non-Gaussianity using fluctuations in temperature and polarization of the Cosmic Microwave Background (CMB). Following Munshi & Heavens (2009), we define a set of power-spectra…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Dipak Munshi , Peter Coles , Asantha Cooray , Alan Heavens , Joseph Smidt

The primordial non-Gaussianity parameters fNL and tauNL may be scale-dependent. We investigate the capability of future measurements of the CMB mu-distortion, which is very sensitive to small scales, and of the large-scale halo bias to test…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-27 Matteo Biagetti , Hideki Perrier , Antonio Riotto , Vincent Desjacques

The weak lensing effects are known to change only weakly the shape of the power spectrum of the Cosmic Microwave Background (CMB) temperature fluctuations. I show here that they nonetheless induce specific non-Gaussian effects that can be…

Astrophysics · Physics 2016-08-30 F. Bernardeau

Several intriguing phenomena, unlikely within the standard inflationary cosmology, were reported in the cosmic microwave background (CMB) data from WMAP and appear to be uncorrelated. Two of these phenomena, termed CMB anomalies, are…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-30 Armando Bernui

We investigate the non-Gaussian signatures in Cosmic Microwave Background (CMB) maps induced by the intervening large-scale structure through weak lensing. In order to measure the deviation from the Gaussian behavior of the intrinsic…

Astrophysics · Physics 2007-05-23 Jens Schmalzing , Masahiro Takada , Toshifumi Futamase

Cosmological inhomogeneities gravitationally deflect radiation propagating from distant sources, transforming the spatial and angular correlation functions of intrinsic source properties. For a gaussian distribution of deflections (e.g.…

Astrophysics · Physics 2007-05-23 Eric V. Linder

We calculate the cosmic microwave background (CMB) angular trispectrum, spherical harmonic transform of the four-point correlation function, from primordial non-Gaussianity in primordial curvature perturbations characterized by a constant…

Astrophysics · Physics 2009-11-11 Noriyuki Kogo , Eiichiro Komatsu

Compensated isocurvature perturbations (CIPs) are modes in which the baryon and dark matter density fluctuations cancel. They arise in the curvaton scenario as well as some models of baryogenesis. While they leave no observable effects on…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 Chen He Heinrich , Daniel Grin , Wayne Hu

Recent studies have shown that the primordial non-Gaussianity affects clustering of dark matter halos through a scale-dependent bias and various constraints on the non-Gaussianity through this scale-dependent bias have been placed. Here we…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-02 Yoshitaka Takeuchi , Kiyotomo Ichiki , Takahiko Matsubara
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