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Related papers: Five parameters are all you need (in $\Lambda$CDM)

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We use a compilation of cosmic microwave anisotropy data to constrain the epoch of reionization in the Universe, as a function of cosmological parameters. We consider spatially-flat cosmologies, varying the matter density $\Omega_0$ (the…

Astrophysics · Physics 2009-10-31 Louise M Griffiths , Domingos Barbosa , Andrew R Liddle

We show that the earliest possible reionisation of the Universe is approximately at $z\simeq 13.5$ and the optical depth is $\tau\simeq 0.17$ in the conventionally accepted $\Lambda$ cold dark matter ($\Lambda$CDM) model with adiabatic…

Astrophysics · Physics 2009-11-07 M. Fukugita , M. Kawasaki

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

We propose an efficient Bayesian MCMC algorithm for estimating cosmological parameters from CMB data without use of likelihood approximations. It builds on a previously developed Gibbs sampling framework that allows for exploration of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-29 Benjamin Racine , Jeffrey B. Jewell , Hans Kristian K. Eriksen , Ingunn K. Wehus

Bayesian statistics and Markov Chain Monte Carlo (MCMC) algorithms have found their place in the field of Cosmology. They have become important mathematical and numerical tools, especially in parameter estimation and model comparison. In…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-02 Luis E. Padilla , Luis O. Tellez , Luis A. Escamilla , J. Alberto Vazquez

The assumption of a flat Universe that follows the cosmological principle, i.e., that the universe is statistically homogeneous and isotropic at large scales, comprises one of the core foundations of the standard cosmological model --…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-24 Mariana L. S. Dias , Antônio F. B. da Cunha , Carlos A. P. Bengaly , Rodrigo S. Gonçalves , Jonathan Morais

Semi-numeric methods have made it possible to efficiently model the epoch of reionisation (EoR). While most implementations involve a reduction to a simple three-parameter model, we introduce a new mass-dependent ionising efficiency…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-12 Daegene Koh , John H. Wise

The current paper provides a comprehensive examination of a dark energy cosmological model in the classical regime, in which a generic scalar field is regarded as a dark energy source. Einstein's field equations are solved in model…

General Relativity and Quantum Cosmology · Physics 2022-09-07 Ritika Nagpal , Shibesh Kumar Jas Pacif , Abhishek Parida

Inhomogeneous reionization gives rise to angular fluctuations in the Cosmic Microwave Background (CMB) optical depth tau(n) to the last scattering surface, correlating different spherical harmonic modes and imprinting characteristic…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-24 Meng Su , Amit P. S. Yadav , Matthew McQuinn , Jaiyul Yoo , Matias Zaldarriaga

Given the persistence of various tensions in the "Cosmic Concordance" -- such as the "Hubble Tension", and possible departures from LambdaCDM time evolution -- seen from combinations of complementary data sets (e.g., Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-19 Brett Bochner , Aiden Jin

We investigate observational constraints on cosmological parameters combining 15 measurements of the transversal BAO scale (obtained free of any fiducial cosmology) with Planck-CMB data to explore the parametric space of some cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-10 Rafael C. Nunes , Santosh K. Yadav , J. F. Jesus , Armando Bernui

The standard cosmological model is sufficiently well constrained that precise estimates can be provided for the redshift of various physically defined times in the chronology of the Universe. For example, it is well known that…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-13 Lukas Tobias Hergt , Douglas Scott

Our current description of the large-scale Universe is now known with a precision undreamt of a generation ago. Within the simple standard cosmological model only six basic parameters are required. The usual parameter set includes…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-30 Douglas Scott , Ali Narimani , Don N. Page

A number of large current experiments aim to detect the signatures of the Cosmic Reionization at redshifts z>6. Their success depends crucially on understanding the character of the reionization process and its observable consequences and…

Astrophysics · Physics 2009-11-13 Ilian T. Iliev , Garrelt Mellema , Ue-Li Pen , J. Richard Bond , Paul R. Shapiro

In the near future, observations of the cosmic microwave background (CMB) anisotropies will provide accurate determinations of many fundamental cosmological parameters. In this paper, we analyse degeneracies among cosmological parameters to…

Astrophysics · Physics 2009-10-30 G. Efstathiou , J. R. Bond

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

We perform a detailed and systematic investigation of the possible impacts of dark stars upon the reionization history of the Universe, and its signatures in the cosmic microwave background (CMB). We compute hydrogen reionization histories,…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-17 Pat Scott , Aparna Venkatesan , Elinore Roebber , Paolo Gondolo , Elena Pierpaoli , Gil Holder

The recombination clumping factor, $C$, is a key parameter in modeling cosmic reionization, but its value is sensitive to the definition of the Intergalactic Medium (IGM). We investigate the clumping factor using the GAMER adaptive mesh…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Yuri Oku , Renyue Cen

We demonstrate the impact on forecasted neutrino mass constraints of extending galaxy clustering and CMB lensing predictions from linear to next-to-leading-order power spectra. The redshift-space 1-loop power spectrum model we adopt…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-04 Aoife Boyle , Fabian Schmidt

We examine the constraints on high-redshift star formation, ultraviolet and X-ray pre-ionization, and the epoch of reionization at redshift z_r, inferred from the recent WMAP-5 measurement, tau_e = 0.084 +/- 0.016, of the electron…

Astrophysics · Physics 2009-11-13 J. Michael Shull , Aparna Venkatesan
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