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Title: Effects of mass varying neutrinos on cosmological parameters as determined from the cosmic microwave background

Authors:
;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1180047
Grant/Contract Number:
FG02-96ER40956
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 90; Journal Issue: 4; Journal ID: ISSN 1550-7998
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Ghalsasi, Akshay, and Nelson, Ann E. Effects of mass varying neutrinos on cosmological parameters as determined from the cosmic microwave background. United States: N. p., 2014. Web. doi:10.1103/PhysRevD.90.045002.
Ghalsasi, Akshay, & Nelson, Ann E. Effects of mass varying neutrinos on cosmological parameters as determined from the cosmic microwave background. United States. doi:10.1103/PhysRevD.90.045002.
Ghalsasi, Akshay, and Nelson, Ann E. Fri . "Effects of mass varying neutrinos on cosmological parameters as determined from the cosmic microwave background". United States. doi:10.1103/PhysRevD.90.045002.
@article{osti_1180047,
title = {Effects of mass varying neutrinos on cosmological parameters as determined from the cosmic microwave background},
author = {Ghalsasi, Akshay and Nelson, Ann E.},
abstractNote = {},
doi = {10.1103/PhysRevD.90.045002},
journal = {Physical Review D},
number = 4,
volume = 90,
place = {United States},
year = {Fri Aug 01 00:00:00 EDT 2014},
month = {Fri Aug 01 00:00:00 EDT 2014}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevD.90.045002

Citation Metrics:
Cited by: 5works
Citation information provided by
Web of Science

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  • We use a frequentist statistical approach to set confidence intervals on the values of cosmological parameters using the MAXIMA-1 and COBE measurements of the angular power spectrum of the cosmic microwave background. We define a Deltachi (2) statistic, simulate the measurements of MAXIMA-1 and COBE, determine the probability distribution of the statistic, and use it and the data to set confidence intervals on several cosmological parameters. We compare the frequentist confidence intervals with Bayesian credible regions. The frequentist and Bayesian approaches give best estimates for the parameters that agree within 15 per cent, and confidence interval widths that agree tomore » within 30 per cent. The results also suggest that a frequentist analysis gives slightly broader confidence intervals than a Bayesian analysis. The frequentist analysis gives values of Omega = 0.89(-0.19)(+0.26), Omega(B) h(2) =0.026(-0.011)(+0.020) and n = 1.02(-0.10)(+0.31), and the Bayesian analysis gives values of Omega = 0.98(-0.19)(+0.14) Omega(B) h(2) =0.029(-0.010)(+0.015), and n = 1.18(-0.23)(+0.10), all at the 95 per cent confidence level.« less
  • Using the latest physical modeling and constrained by the most recent data, we develop a phenomenological parameterized model of the contributions to intensity and polarization maps at millimeter wavelengths from external galaxies and Sunyaev-Zeldovich effects. We find such modeling to be necessary for estimation of cosmological parameters from Planck data. For example, ignoring the clustering of the infrared background would result in a bias in n{sub s} of 7{sigma} in the context of an eight-parameter cosmological model. We show that the simultaneous marginalization over a full foreground model can eliminate such biases, while increasing the statistical uncertainty in cosmological parametersmore » by less than 20%. The small increases in uncertainty can be significantly reduced with the inclusion of higher-resolution ground-based data. The multi-frequency analysis we employ involves modeling 46 total power spectra and marginalization over 17 foreground parameters. We show that we can also reduce the data to a best estimate of the cosmic microwave background power spectra, with just two principal components (with constrained amplitudes) describing residual foreground contamination.« less
  • The cosmic microwave background anisotropy is sensitive to the slope and amplitude of primordial energy density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history, etc. In this Letter, we examine the degree to which these factors can be separately resolved from combined small- and large-angular-scale anisotropy observations. We isolate directions of degeneracy in this cosmic parameter space, but note that other cosmic observations can break the degeneracy.
  • Cosmological magnetic fields induce temperature and polarization fluctuations in the cosmic microwave background (CMB) radiation. A cosmological magnetic field with current amplitude of order 10{sup -9} G is detectable via observations of CMB anisotropies. This magnetic field (with or without helicity) generates vector perturbations through vortical motions of the primordial plasma. This paper shows that magnetic field helicity induces parity-odd cross correlations between CMB temperature and B-polarization fluctuations and between E- and B-polarization fluctuations, correlations which are zero for fields with no helicity (or for any parity-invariant source). Helical fields also contribute to parity-even temperature and polarization anisotropies, canceling partmore » of the contribution from the symmetric component of the magnetic field. We give analytic approximations for all CMB temperature and polarization anisotropy vector power spectra due to helical magnetic fields. These power spectra offer a method for detecting cosmological helical magnetic fields, particularly when combined with Faraday rotation measurements which are insensitive to helicity.« less
  • We estimate the effect of the experimental uncertainty in the measurement of the temperature of the cosmic microwave background (CMB) on the extraction of cosmological parameters from future CMB surveys. We find that even for an ideal experiment limited only by cosmic variance up to l=2500 for both the temperature and polarization measurements, the projected cosmological parameter errors are remarkably robust against the uncertainty of 1 mK in the firas CMB temperature monopole measurement. The maximum degradation in sensitivity is 20%, for the baryon density estimate, relative to the case in which the monopole is known infinitely well. While thismore » degradation is acceptable, we note that reducing the uncertainty in the current temperature measurement by a factor of five will bring it down to {approx}1%. We also estimate the effect of the uncertainty in the dipole temperature measurement. Assuming the overall calibration of the data to be dominated by the dipole error of 0.2% from firas, the sensitivity degradation is insignificant and does not exceed 10% in any parameter direction.« less