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Several recent papers have made claims about the detection of an asymmetric distribution of large scale power in the cosmic microwave background anisotropy as measured by the WMAP satellite. In this paper, we investigate how the estimates…

Astrophysics · Physics 2009-11-10 F. K. Hansen , A. Balbi , A. J. Banday , K. M. Gorski

The cosmic microwave background (CMB) anisotropies have turned out to represent one of the most stringent 'bottle necks' for scenarios of large scale structure formation. As a possibility to relax this constraint, it has been proposed that…

Astrophysics · Physics 2009-10-22 Ruth Durrer

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

The 21-cm power spectrum of reionization is a promising probe for cosmology and fundamental physics. Exploiting this new observable, however, requires fast predictors capable of efficiently scanning the very large parameter space of…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Aurel Schneider , Timothée Schaeffer , Sambit K. Giri

Future data from galaxy redshift surveys, combined with high-resolutions maps of the cosmic microwave background, will enable measurements of the pairwise kinematic Sunyaev-Zel'dovich (kSZ) signal with unprecedented statistical…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-02 Samuel Flender , Daisuke Nagai , Michael McDonald

Using a Bayesian framework, we quantify what current observations imply about the history of the epoch of reionisation (EoR). We use a popular, three-parameter EoR model, flexible enough to accommodate a wide range of physically-plausible…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-01 Bradley Greig , Andrei Mesinger

New low frequency radio telescopes currently being built open up the possibility of observing the 21-cm radiation before the Epoch of Reionization in the future, in particular at redshifts 200 > z > 30, also known as the dark ages. At these…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-03 Rishi Khatri , Benjamin D. Wandelt

We investigate the effect of patchy reionization on the cosmic microwave background temperature. An anisotropic optical depth tau (theta) alters the TT power spectrum on small scales l > 2000. We make use of the correlation between the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Aravind Natarajan , Nick Battaglia , Hy Trac , Ue Li Pen , Abraham Loeb

The 21-cm PDF (i.e., distribution of pixel brightness temperatures) is expected to be highly non-Gaussian during reionization and to provide important information on the distribution of density and ionization. We measure the 21-cm PDF as a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Kazuhide Ichikawa , Rennan Barkana , Ilian T. Iliev , Garrelt Mellema , Paul Shapiro

We present constraints on cosmological and star formation parameters based on combining observations of the Wilkinson Microwave Anisotropy Probe (WMAP) and high-redshift quasars from the Sloan Digital Sky Survey (SDSS). We use a…

Astrophysics · Physics 2009-11-07 Weihsueh A. Chiu , Xiaohui Fan , Jeremiah P. Ostriker

Upcoming measurements of the kinetic Sunyaev-Zel'dovich (kSZ) effect, which results from Cosmic Microwave Background (CMB) photons scattering off moving electrons, offer a powerful probe of the Epoch of Reionization (EoR). The kSZ signal…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-24 Farshid Farhadi Khouzani , Abinash Kumar Shaw , Paul La Plante , Bryar Mustafa Shareef , Laxmi Gewali

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

We review the observable consequences of the epoch of reionization (EoR) on the cosmic microwave background (CMB), and the resulting constraints on the EoR. We discuss how Thomson scattering with the free electrons produced during EoR…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Christian L. Reichardt

The first-year Wilkinson Microwave Anisotropy Probe data suggest a high optical depth for Thomson scattering of 0.17 +/- 0.04, implying that the universe was reionized at an early epoch, z ~ 20. Such early reionization is likely to be…

Astrophysics · Physics 2009-11-10 Xuelei Chen , Asantha Cooray , Naoki Yoshida , Naoshi Sugiyama

The first generation (Pop-III) stars can ionize 1-10% of the universe by $z=15$, when the metal-enriched (Pop-II) stars may contribute negligibly to the ionization. This low ionization tail might leave detectable imprints on the large-scale…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-13 Xiaohan Wu , Matthew McQuinn , Daniel Eisenstein , Vid Irsic

We propose a new reionization probe that uses cosmic microwave background (CMB) observations; the cross-correlation between fluctuations in the CMB optical depth which probes the integrated electron density, $\delta\tau$, and the Compton…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-15 Toshiya Namikawa , Anirban Roy , Blake D. Sherwin , Nicholas Battaglia , David N. Spergel

A possible way to study the reionization of cosmic hydrogen is by observing the large ionized regions (bubbles) around bright individual sources, e.g., quasars, using the redshifted 21 cm signal. It has already been shown that matched…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-17 Raghunath Ghara , T. Roy Choudhury

The large-angle polarization anisotropies in the Cosmic Microwave Background (CMB) arise from Thomson scattering of CMB photons off free electrons in the post-recombination Universe. In the standard $\Lambda$ cold dark matter cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-24 Hanyu Cheng , Ziwen Yin , Eleonora Di Valentino , David J. E. Marsh , Luca Visinelli

The detection of large angular scale $B$-mode in the Cosmic Microwave Background (CMB) polarization signal will open a direct window into not only the primary CMB anisotropies caused by the primordial gravitational waves (PGW) originating…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-26 Divesh Jain , Suvodip Mukherjee , Tirthankar Roy Choudhury

We explore the ability of observations of the global brightness temperature of the 21-cm signal to constrain the reionization history and the properties of the ionizing sources. In order to describe the reionization signal, we employ either…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Andrea Morandi , Rennan Barkana
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