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The simple assumption of an instantaneous reionization of the Universe may bias estimates of cosmological parameters. In this paper a model-independent principal component method for the reionization history is applied to give constraints…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-21 Wei-Ming Dai , Zong-Kuan Guo , Rong-Gen Cai

We compute the B-mode polarization power spectrum of the CMB from an epoch of inhomogeneous reionization, using a simple model in which HII regions are represented by ionized spherical bubbles with a log normal distribution of sizes whose…

Astrophysics · Physics 2008-11-26 Michael J. Mortonson , Wayne Hu

Based on the work by Mitra, Choudhury & Ferrara (2010), we obtain model-independent constraints on reionization from cosmic microwave background (CMB) and QSO absorption line data by decomposing the function N_{ion}(z) (the number of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Sourav Mitra , T. Roy Choudhury , Andrea Ferrara

Modelling reionization often requires significant assumptions about the properties of ionizing sources. Here, we infer the total output of hydrogen-ionizing photons (the ionizing emissivity, $\dot{N}_\textrm{ion}$) at $z=4-14$ from current…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-12 Charlotte A. Mason , Rohan P. Naidu , Sandro Tacchella , Joel Leja

We summarize existing constraints on the epoch of reionization and discuss the observational probes that are sensitive to the process. We focus on the role large scale polarization can play. Polarization probes the integrated optical depth…

The epoch of the end of reionization and the Thomson optical depth to the cosmic microwave background depend on the power spectrum amplitude on small scales and on the ionizing photon emissivity per unit mass in collapsed halos. In this…

Astrophysics · Physics 2007-05-23 L. A. Popa

Cosmological parameter measurements from CMB experiments such as Planck, ACTpol, SPTpol and other high resolution follow-ons fundamentally rely on the accuracy of the assumed recombination model, or one with well prescribed uncertainties.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Marzieh Farhang , J. Richard Bond , Jens Chluba

We explore the constraints on the history of reionization from Planck 2015 Cosmic Microwave Background (CMB) data and we derive the forecasts for future CMB observations. We consider a class of monotonic histories of reionization as…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Dhiraj Kumar Hazra , Daniela Paoletti , Fabio Finelli , George F. Smoot

Spectral features in the CMB energy spectrum contain a wealth of information about the physical processes in the early Universe, z < 2 x 10^6. The CMB spectral distortions are complementary to all other probes of cosmology. In fact, most of…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-12 Rashid A. Sunyaev , Rishi Khatri

We investigate the potential of second generation measurements of redshifted 21 cm radiation from before and during the epoch of reionization (EOR) to reconstruct the matter density fluctuations along the line of sight. To do so we…

Astrophysics · Physics 2008-11-26 Oliver Zahn , Matias Zaldarriaga

The effects of reionization, occurring after standard recombination in cold dark matter-dominated models, on CMB anisotropies are investigated. Late-time reionization reduces the CMB anisotropies, in particular, on degree scales. It is…

Astrophysics · Physics 2009-10-22 Naoshi Sugiyama , Joseph Silk , Nicola Vittorio

We investigate the constraints on the reionization history of the Universe from a joint analysis of the cosmic microwave background and neutral hydrogen fraction data. The $\tanh$ parametrization and principal component analysis methods are…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 Wei-Ming Dai , Yin-Zhe Ma , Zong-Kuan Guo , Rong-Gen Cai

The accurate understanding of the ionization history of the Universe plays a fundamental role in modern cosmology. It includes a phase of cosmological reionization after the standard recombination epoch, possibly associated to the early…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-03 Tiziana Trombetti , Carlo Burigana

We use the recent CMB power spectrum measurement by the Maxima experiment (Hanany et al. 2000) to constrain the redshift of reionization z_re. This becomes possible by combining the CMB data with cosmological parameters from various…

Astrophysics · Physics 2007-05-23 Jens Schmalzing , Jesper Sommer-Larsen , Martin Goetz

Estimates of inflationary parameters from the CMB B-mode polarization spectrum on the largest scales depend on knowledge of the reionization history, especially at low tensor-to-scalar ratio. Assuming an incorrect reionization history in…

Astrophysics · Physics 2008-11-26 Michael J. Mortonson , Wayne Hu

Reionization of the cosmic neutral hydrogen by the first stars in the Universe is an inhomogeneous process which produces spatial fluctuations in free electron density. These fluctuations lead to observable signatures in cosmological probes…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-11 Sourabh Paul , Suvodip Mukherjee , Tirthankar Roy Choudhury

The thermodynamic and dynamical properties of a variable dark energy model with density scaling as rho_x \propto (1+z)^m, z being the redshift, are discussed following the outline of Jetzer et al. This kind of models are proven to lead to…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-08 Philippe Jetzer , Crescenzo Tortora

The WMAP first year detection of a high redshift reionization through its imprints on CMB anisotropy T and TE mode angular power spectra calls for a better comprehension of the universe ionization and thermal history after the standard…

Astrophysics · Physics 2007-05-23 C. Burigana , L. A. Popa , F. Finelli , R. Salvaterra , G. De Zotti , N. Mandolesi

The free-electron population during the reionized epoch rescatters CMB temperature quadrupole and generates a now well-known polarization signal at large angular scales. While this contribution has been detected in the…

Astrophysics · Physics 2009-11-10 Asantha Cooray

We combine observational data on a dozen independent cosmic properties at high-$z$ with the information on reionization drawn from the spectra of distant luminous sources and the cosmic microwave background (CMB) to constrain the…