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Calculations of cosmological hydrogen recombination are vital for the extraction of cosmological parameters from cosmic microwave background (CMB) observations, and for imposing constraints to inflation and re-ionization. The Planck}…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-22 Daniel Grin , Christopher M. Hirata

The energy spectrum of the cosmic microwave background (CMB) allows constraining episodes of energy release in the early Universe. In this paper we revisit and refine the computations of the cosmological thermalization problem. For this…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 J. Chluba , R. A. Sunyaev

We calculate the recombination spectra of the He-like ions He~I, C~V, N~VI, O~VII, Ne~IX, Mg~XI, Si~XIII, S~XV, Ar~XVII, Ca~XIX, and Fe~XXV. We include the following physical processes: radiative recombination, dielectronic recombination,…

Astrophysics · Physics 2009-10-31 M. A. Bautista , T. R. Kallman

The formation of the cosmic microwave background radiation (CMBR) provides a very powerful probe of the early universe at the epoch of recombination. Specifically, it is possible to constrain the variation of fundamental physical constants…

Astrophysics · Physics 2009-10-31 Steen Hannestad

The primordial power spectrum describes the initial perturbations in the Universe which eventually grew into the large-scale structure we observe today, and thereby provides an indirect probe of inflation or other structure-formation…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-02 P. Paykari , F. Lanusse , J. -L. Starck , F. Sureau , J. Bobin

We show that by combining measurements of the temperature and polarization anisotropies of the Cosmic Microwave Background (CMB), future experiments will tightly constrain the expansion rate of the universe during recombination. A change in…

Astrophysics · Physics 2009-11-07 Oliver Zahn , Matias Zaldarriaga

The damping of primordial perturbations at small scales gives rise to distortions of the cosmic microwave background (CMB). Here, the dependence of the distortion on the different types of cosmological initial conditions is explored,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-18 Jens Chluba , Daniel Grin

More than half of the atoms in the Universe recombined via forbidden transitions, so that accurate treatment of the forbidden channels is important in order to follow the cosmological recombination process with the level of precision…

Astrophysics · Physics 2008-11-26 Wan Yan Wong , Douglas Scott

Under the standard model for recombination of the primeval plasma, and the cold dark matter model for structure formation, recent measurements of the first peak in the angular power spectrum of the cosmic microwave background temperature…

Astrophysics · Physics 2009-10-31 P. J. E. Peebles , Sara Seager , Wayne Hu

Given observations of B-mode polarization power spectrum of the cosmic microwave background (CMB), we can reconstruct power spectra of primordial tensor modes from the early Universe without assuming their functional form such as a…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-20 Takashi Hiramatsu , Eiichiro Komatsu , Masashi Hazumi , Misao Sasaki

Following the pioneering observations with COBE in the early 1990s, studies of the cosmic microwave background (CMB) have focused on temperature and polarization anisotropies. CMB spectral distortions - tiny departures of the CMB energy…

Ever refined cosmological measurements have established the $\Lambda$CDM concordance model, with the key cosmological parameters being determined to percent-level precision today. This allows us to make explicit predictions for the spectral…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-23 Jens Chluba

We reconstruct the power spectrum of primordial curvature perturbations by applying a well-validated non-parametric technique employing Tikhonov regularisation to the first data release from the Planck satellite. To improve the…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-31 Paul Hunt , Subir Sarkar

It is shown that taking into account a recoil for radiation scattering in the Ly-alpha line can lead to a noticable acceleration of primordial hydrogen recombination. Thus for LambdaCDM model a decrease of ionization degree exceeds 1% for…

Astrophysics · Physics 2009-11-13 S. I. Grachev , V. K. Dubrovich

The primordial curvature fluctuation spectrum is reconstructed by the cosmic inversion method using the five-year WMAP data of the cosmic microwave background temperature anisotropy. We apply the covariance matrix analysis and decompose the…

Astrophysics · Physics 2008-12-30 Ryo Nagata , Jun'ichi Yokoyama

A second plateau in the harmonic spectra of laser-driven two-electron atoms is observed both in the numerical solution of a low-dimensional model helium atom and using an extended strong field approximation. It is shown that the harmonics…

Atomic Physics · Physics 2009-11-13 P. Koval , F. Wilken , D. Bauer , C. H. Keitel

The HeII->HeI recombination of primordial helium plasma (z = 1500 - 3000) is considered in terms of the standard cosmological model. This process affects the formation of cosmic microwave background anisotropy and spectral distortions. We…

Astrophysics · Physics 2011-08-31 E. E. Kholupenko , A. V. Ivanchik , D. A. Varshalovich

Spectral distortions of the cosmic microwave background (CMB) provide a unique tool for learning about the early phases of cosmic history, reaching deep into the primordial Universe. At redshifts $z<10^6$, thermalization processes become…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-04 Jens Chluba , Andrea Ravenni , Sandeep Kumar Acharya

Molecular beam experiments that use low-temperature bolometers as (energy-) detectors are well suited to the study of physisorption and recombination of hydrogen on low-temperature surfaces. Experiments where this technique is combined with…

Chemical Physics · Physics 2007-05-23 Thomas Govers

Photons emitted during the formation of primordial hydrogen and helium atoms over the Epoch of Recombination are expected to be preserved as additive distortions to the Cosmic Microwave Background (CMB) spectrum. The 'ripple' like spectral…

Instrumentation and Methods for Astrophysics · Physics 2024-12-02 Dhashin Krishna , Mayuri Sathyanarayana Rao