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We reexamine the evidence of the hemispherical power asymmetry, detected in the CMB WMAP data using a new method. At first, we analyze the hemispherical variance ratios and compare these with simulated distributions. Secondly, working…

Astrophysics · Physics 2014-11-18 Bartosz Lew

We implement and investigate a method for measuring departures from scale-invariance, both scale-dependent as well as scale-free, in the primordial power spectrum of density perturbations using cosmic microwave background (CMB) C_l data and…

Astrophysics · Physics 2009-11-11 Samuel Leach

Unmeasured spatial confounding complicates exposure effect estimation in environmental health studies. This problem is exacerbated in studies with multiple health outcomes and environmental exposure variables, as the source and magnitude of…

Foreground removal remains an ongoing challenge in radio cosmology, and increasingly sensitive experiments necessitate more robust analysis techniques. In this work, we model simulated data from a single-dish intensity mapping experiment,…

Instrumentation and Methods for Astrophysics · Physics 2026-04-30 Geoff G. Murphy , Philip Bull , Mario G. Santos , Zheng Zhang , Steven Cunnington

Intensity mapping of the HI brightness temperature provides a unique way of tracing large-scale structures of the Universe up to the largest possible scales. This is achieved by using a low angular resolution radio telescopes to detect…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-02 Obinna Umeh

We explore the possible impact of galactic and extragalactic foregrounds on measurements of the cosmic microwave background (CMB). We find that, given our present understanding of the foregrounds, they are unlikely to qualitatively affect…

Astrophysics · Physics 2016-08-30 Lloyd Knox

Cosmic shear tomography has emerged as one of the most promising tools to both investigate the nature of dark energy and discriminate between General Relativity and modified gravity theories. In order to successfully achieve these goals,…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 V. F. Cardone , M. Martinelli , E. Calabrese , S. Galli , Z. Huang , R. Maoli , A. Melchiorri , R. Scaramella

We describe a simple but efficient method for deriving a consistent set of monopole and dipole corrections for multi-frequency sky map data sets, allowing robust parametric component separation with the same data set. The computational core…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-01 I. K. Wehus , U. Fuskeland , H. K. Eriksen , A. J. Banday , C. Dickinson , T Ghosh , K. M. Gorski , C. R. Lawrence , J. P. Leahy , D. Maino , P. Reich , W. Reich

Data analysis from upcoming large galaxy redshift surveys, such as Euclid and DESI will significantly improve constraints on cosmological parameters. To optimally extract the information from these galaxy surveys, it is important to control…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 S. Gouyou Beauchamps , P. Baratta , S. Escoffier , W. Gillard , J. Bel , J. Bautista , C. Carbone

We use the results of previous work building a halo model formalism for the distribution of neutral hydrogen, along with experimental parameters of future radio facilities, to place forecasts on astrophysical and cosmological parameters…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-20 Hamsa Padmanabhan , Alexandre Refregier , Adam Amara

The disagreement between low- and high-redshift measurements of the Hubble parameter is emerging as a serious challenge to the standard model of cosmology. We develop a covariant cosmographic analysis of the Hubble parameter in a general…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-13 Roy Maartens , Jessica Santiago , Chris Clarkson , Basheer Kalbouneh , Christian Marinoni

Several anomalies appear to be present in the large-angle cosmic microwave background (CMB) anisotropy maps of WMAP, including the alignment of large-scale multipoles. Models in which isotropy is spontaneously broken (e.g., by a scalar…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Haoxuan Zheng , Emory F. Bunn

We find a simple, accurate model for the covariance matrix of the real-space cosmological matter power spectrum on slightly nonlinear scales (k~0.1-0.8 h/Mpc at z=0), where off-diagonal matrix elements become substantial. The model includes…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-30 Mark C. Neyrinck

Methods are studied to compute the boosting effects produced by the observer motion that modifies and transfers to higher l the isotropic monopole frequency spectrum of the cosmic background. Explicit analytical solutions for spherical…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-11 Tiziana Trombetti , Carlo Burigana , Marco Tucci , Luigi Toffolatti

We reconstruct the shape of the primordial power spectrum from the latest cosmic microwave background data, including the new results from the Wilkinson Microwave Anisotropy Probe (WMAP), and large scale structure data from the two degree…

Astrophysics · Physics 2009-11-07 S. L. Bridle , A. M. Lewis , J. Weller , G. Efstathiou

We present posterior sample-based cosmic microwave background (CMB) constraints from Planck LFI and WMAP observations derived through global end-to-end Bayesian processing. We use these samples to study correlations between CMB, foreground,…

Intensity mapping of the neutral hydrogen brightness temperature promises to provide a three-dimensional view of the universe on very large scales. Nonlinear effects are typically thought to alter only the small-scale power, but we show how…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-18 Obinna Umeh , Roy Maartens , Mario Santos

The natural outcome of theoretical calculations of microwave background anisotropy is the angular power spectrum ${\cal C}_\ell$ as a function of multipole number $\ell$. Experimental ${\cal C}_\ell$'s are needed for direct comparison.…

Astrophysics · Physics 2009-09-25 J. Richard Bond

In recent years the goal of estimating different cosmological parameters precisely has set new challenges in the effort to accurately measure the angular power spectrum of CMB. This has required removal of foreground contamination as well…

Astrophysics · Physics 2008-11-26 Rajib Saha , Simon Prunet , Pankaj Jain , Tarun Souradeep
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