English
Related papers

Related papers: Improved constraints on lepton asymmetry from the …

200 papers

Diffusion damping of the cosmic microwave background (CMB) power spectrum results from imperfect photon-baryon coupling in the pre-recombination plasma. At redshift $5 \times 10^4 < z < 2 \times 10^6$, the plasma acquires an effective…

We study Planck 2015 cosmic microwave background (CMB) anisotropy data using the energy density inhomogeneity power spectrum generated by quantum fluctuations during an early epoch of inflation in the non-flat $\Lambda$CDM model. Unlike…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Junpei Ooba , Bharat Ratra , Naoshi Sugiyama

A key prediction of cosmological theories for the origin and evolution of structure in the Universe is the existence of a `Doppler peak' in the angular power spectrum of cosmic microwave background (CMB) fluctuations. We present new results…

Astrophysics · Physics 2020-11-25 S. Hancock , G. Rocha , A. N. Lasenby , C. M. Gutierrez

Big Bang Nucleosynthesis (BBN) relates key cosmological parameters to the primordial abundance of light elements. In this paper, we point out that the recent observations of Cosmic Microwave Background anisotropies by the Planck satellite…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-06 Eleonora Di Valentino , Carlo Gustavino , Julien Lesgourgues , Gianpiero Mangano , Alessandro Melchiorri , Gennaro Miele , Ofelia Pisanti

We find that current Cosmic Microwave Background (CMB) anisotropy data strongly constrain the mean spatial curvature of the Universe to be near zero, or, equivalently, the total energy density to be near critical-as predicted by inflation.…

Astrophysics · Physics 2009-10-31 S. Dodelson , L. Knox

Possible existence of the primordial magnetic fields has affected the structure formation of the universe. In this paper it is shown that the initial conditions for density perturbations with magnetic fields derived in previous works are…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-20 Kazuhiko Kojima , Kiyotomo Ichiki

We examine the cosmic microwave background (CMB) anisotropy for signatures of early quintessence dark energy -- a non-negligible quintessence energy density during the recombination and structure formation eras. In contrast to a…

Astrophysics · Physics 2007-05-23 Christian M Mueller

We present a new constraint on the effective number of relativistic species in the early universe, $N_{\rm eff}$, by combining recent primordial helium abundance measurements from the Large Binocular Telescope $Y_p$ Project with primordial…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-23 Samuel Goldstein , J. Colin Hill

Cosmic microwave background (CMB) determinations of the baryon-to-photon ratio $\eta \propto \Omega_{\rm baryon} h^2$ will remove the last free parameter from (standard) big bang nucleosynthesis (BBN) calculations. This will make BBN a much…

Astrophysics · Physics 2008-11-26 Richard H. Cyburt , Brian D. Fields , Keith A. Olive

We investigate how large lepton asymmetries affect the evolution of the early universe at times before big bang nucleosynthesis and in particular how they influence the relic density of WIMP dark matter. In comparison to the standard…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Maik Stuke , Dominik J Schwarz , Glenn Starkman

We use a wide range of observations to constrain cosmological models possessing a significant asymmetry in the lepton sector, which offer perhaps the best chance of reconciling a critical-density Universe with current observations. The…

Astrophysics · Physics 2009-11-06 Julien Lesgourgues , Andrew R. Liddle

The radiative component of the Universe has a characteristic impact on both large scale structure (LSS) and the cosmic microwave background radiation (CMB). We use the recent WMAP data, together with previous CBI data and 2dF matter power…

Astrophysics · Physics 2009-11-07 Elena Pierpaoli

The origin of power asymmetry and other measures of statistical anisotropy on the largest scales of the universe, as manifested in Cosmic Microwave Background (CMB) and large-scale structure data, is a long-standing open question in…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-12 Pablo Fosalba , Enrique Gaztanaga

We study the effect of neutrino degeneracy on primordial nucleosynthesis in a universe in which the cosmological scale factor evolves linearly with time. The degeneracy parameter of electron type neutrinos ($\xi_e$) determines the $n/p$…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-02 Parminder Singh , Daksh Lohiya

In universes with significant curvature or cosmological constant, cosmic microwave background (CMB) anisotropies are created very recently via the Rees-Sciama or integrated Sachs-Wolfe effects. This causes the CMB anisotropies to become…

Astrophysics · Physics 2009-10-30 S. P. Boughn , R. G. Crittenden , N. G. Turok

We present constraints on extensions to the $\Lambda$CDM cosmological model from measurements of the $E$-mode polarization auto-power spectrum and the temperature-$E$-mode cross-power spectrum of the cosmic microwave background (CMB) made…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-13 L. Balkenhol , D. Dutcher , P. A. R. Ade , Z. Ahmed , E. Anderes , A. J. Anderson , M. Archipley , J. S. Avva , K. Aylor , P. S. Barry , R. Basu Thakur , K. Benabed , A. N. Bender , B. A. Benson , F. Bianchini , L. E. Bleem , F. R. Bouchet , L. Bryant , K. Byrum , J. E. Carlstrom , F. W. Carter , T. W. Cecil , C. L. Chang , P. Chaubal , G. Chen , H. -M. Cho , T. -L. Chou , J. -F. Cliche , T. M. Crawford , A. Cukierman , C. Daley , T. de Haan , E. V. Denison , K. Dibert , J. Ding , M. A. Dobbs , W. Everett , C. Feng , K. R. Ferguson , A. Foster , J. Fu , S. Galli , A. E. Gambrel , R. W. Gardner , N. Goeckner-Wald , R. Gualtieri , S. Guns , N. Gupta , R. Guyser , N. W. Halverson , A. H. Harke-Hosemann , N. L. Harrington , J. W. Henning , G. C. Hilton , E. Hivon , G. P. Holder , W. L. Holzapfel , J. C. Hood , D. Howe , N. Huang , K. D. Irwin , O. B. Jeong , M. Jonas , A. Jones , T. S. Khaire , L. Knox , A. M. Kofman , M. Korman , D. L. Kubik , S. Kuhlmann , C. -L. Kuo , A. T. Lee , E. M. Leitch , A. E. Lowitz , C. Lu , S. S. Meyer , D. Michalik , M. Millea , J. Montgomery , A. Nadolski , T. Natoli , H. Nguyen , G. I. Noble , V. Novosad , Y. Omori , S. Padin , Z. Pan , P. Paschos , J. Pearson , C. M. Posada , K. Prabhu , W. Quan , A. Rahlin , C. L. Reichardt , D. Riebel , B. Riedel , M. Rouble , J. E. Ruhl , J. T. Sayre , E. Schiappucci , E. Shirokoff , G. Smecher , J. A. Sobrin , A. A. Stark , J. Stephen , K. T. Story , A. Suzuki , K. L. Thompson , B. Thorne , C. Tucker , C. Umilta , L. R. Vale , K. Vanderlinde , J. D. Vieira , G. Wang , N. Whitehorn , W. L. K. Wu , V. Yefremenko , K. W. Yoon , M. R. Young

We reanalyze the cosmological constraints on the existence of a net universal lepton asymmetry and neutrino degeneracy based upon the latest high resolution CMB sky maps from BOOMERANG, DASI, and MAXIMA-1. We generate likelihood functions…

Astrophysics · Physics 2009-11-07 M. Orito , T. Kajino , G. J. Mathews , Y. Wang

The recent analysis of the cosmic microwave background data carried out by the WMAP team seems to show that the sum of the neutrino masses is <0.7 eV. However, this result is not model-independent, depending on precise assumptions on the…

Astrophysics · Physics 2009-11-10 Massimiliano Lattanzi

In this work we present the results of our numerical analysis of the effect of lepton asymmetries L on neutrino oscillations and consequently on helium production in a model of cosmological nucleosynthesis with active-sterile neutrino…

High Energy Physics - Phenomenology · Physics 2009-10-31 Daniela Kirilova , Mihail Chizhov

We discuss the cosmological implications of the new constraints on the power spectrum of the Cosmic Microwave Background Anisotropy derived from a new high resolution analysis of the MAXIMA-1 measurement (Lee et al. 2001). The power…