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Related papers: "Sample Variance" in Small-Scale CMB Anisotropy Ex…

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Much attention has been given to the problem of estimating cosmological parameters from the $C_l$ measured by future experiments. Many of the approaches which are being used either invoke poorly controlled approximations or are…

Astrophysics · Physics 2007-05-23 Benjamin D. Wandelt , Eric Hivon , Krzysztof M. Gorski

Cosmic microwave background (CMB) anisotropies probe the primordial density field at the edge of the observable Universe. There is a limiting precision (``cosmic variance'') with which anisotropies can determine the amplitude of primordial…

Astrophysics · Physics 2016-08-25 Marc Kamionkowski , Abraham Loeb

Angular anisotropy techniques for cosmic diffuse radiation maps are powerful probes, even for quite small data sets. A popular observable is the angular power spectrum; we present a detailed study applicable to any unbinned source skymap…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Sheldon S. Campbell

Non-Gaussian distributions of cosmic microwave background (CMB) anisotropies have been proposed to reconcile the discrepancies between different experiments at half-degree scales (Coulson et al. 1994). Each experiment probes a different…

Astrophysics · Physics 2009-10-22 Xiaochun Luo

The primary results of most observations of cosmic microwave background (CMB) anisotropy are estimates of the angular power spectrum averaged through some broad band, called band-powers. These estimates are in turn what are used to produce…

Astrophysics · Physics 2016-08-25 Lloyd Knox

Estimation of the angular power spectrum of the Cosmic Microwave Background (CMB) on a small patch of sky is usually plagued by serious spectral leakage, specially when the map has a hard edge. Even on a full sky map, point source masks can…

Astrophysics · Physics 2009-11-06 Sudeep Das , Amir Hajian , David N. Spergel

We address the $\simeq 4.4\sigma$ tension between local and the CMB measurements of the Hubble Constant using simulated Type Ia Supernova (SN) data-sets. We probe its directional dependence by means of a hemispherical comparison through the…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-18 Carlos A. P. Bengaly , Uendert Andrade , Jailson S. Alcaniz

Band-power estimates of cosmic microwave background fluctuations are now routinely used to place constraints on cosmological parameters. For this to be done in a rigorous fashion, the full likelihood function of band-power estimates must be…

Astrophysics · Physics 2011-05-23 J. G. Bartlett , M. Douspis , A. Blanchard , M. Le Dour

We consider several factors concerning the design of observing strategies in Cosmic Microwave Background (CMB) anisotropy experiments. First we consider the number of independent points on the sky one should observe given a fixed observing…

Astrophysics · Physics 2007-05-23 R. K. Schaefer , L. Piccirillo

The current suite of results from Cosmic Microwave Background anisotropy experiments is fulfilling the promise of providing extraordinary levels of discrimination between cosmological models. We calculate a binned anisotropy power spectrum,…

Astrophysics · Physics 2007-05-23 Elena Pierpaoli , Douglas Scott , Martin White

A previous work (Monteser\'in et al. 2008) estimated the CMB variance from the three-year WMAP data, finding a lower value than expected from Gaussian simulations using the WMAP best-fit cosmological model. We repeat the analysis on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. Cruz , P. Vielva , E. Martínez-González , R. B. Barreiro

We compute the effects induced by the use of small CMB maps on the measurement of the $\cl{l}$ coefficients of the angular power spectrum and show that small systematic effects have to be taken into account. We also compute numerically the…

Astrophysics · Physics 2007-08-06 C. Magneville , J. P. Pansart

Recent detections of cosmic microwave background (CMB) anisotropy at half-degree angular scales show considerable scatter in the reported amplitude even at similar angular resolution. We use Monte Carlo techniques to simulate the current…

Astrophysics · Physics 2007-05-23 A. Kogut , G. Hinshaw

The CMB anisotropy depends sensitively upon the slope and amplitude of primordial density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history, {\it etc.} We report…

Astrophysics · Physics 2009-09-25 J. Richard Bond , Richard L. Davis , Paul J. Steinhardt

Anisotropy data analysis leaves a significant degeneracy between primeval spectral index (n_s) and cosmic opacity to CMB photons (\tau). Low--l polarization measures, in principle, can remove it. We perform a likelihood analysis to see how…

Astrophysics · Physics 2009-11-07 L. P. L. Colombo , S. A. Bonometto

The study of cosmic birefringence through Cosmic Microwave Background (CMB) experiments is a key research area in cosmology and particle physics, providing a critical test for Lorentz and CPT symmetries. This paper focuses on an upcoming…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 Yiwei Zhong , Hongbo Cai , Si-Yu Li , Yang Liu , Mingzhe Li , Wenjuan Fang

Measurement of Cosmic Microwave Background (CMB) anisotropies has been playing a lead role in precision cosmology by providing some of the tightest constrains on cosmological models and parameters. However, precision can only be meaningful…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-16 Santanu Das , Sanjit Mitra , Sonu Tabitha Paulson

We study the impact of nearby inhomogeneities on an observer's inference of the Hubble constant. Large-scale structures induce a dependence of cosmological parameters on observer position as well as an anisotropic variance of those…

General Relativity and Quantum Cosmology · Physics 2024-02-16 Hayley J. Macpherson

Fundamental information about the Universe is encoded in anisotropies of the Cosmic Microwave Background (CMB) radiation. To make full use of this information, an experiment must image the entire sky with the angular resolution,…

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
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