Dark Radiation in extended cosmological scenarios
arXiv:1206.0109 · doi:10.1103/PhysRevD.86.043509
Abstract
Recent cosmological data have provided evidence for a "dark" relativistic background at high statistical significance. Parameterized in terms of the number of relativistic degrees of freedom Neff, however, the current data seems to indicate a higher value than the one expected in the standard scenario based on three active neutrinos. This dark radiation component can be characterized not only by its abundance but also by its clustering properties, as its effective sound speed and its viscosity parameter. It is therefore crucial to study the correlations among the dark radiation properties and key cosmological parameters, as the dark energy equation of state or the running of the scalar spectral index, with current and future CMB data. We find that dark radiation with viscosity parameters different from their standard values may be misinterpreted as an evolving dark energy component or as a running spectral index in the power spectrum of primordial fluctuations.
7 pages, 6 figures
References in corpus (12)
- Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation
- A new cosmic microwave background constraint to primordial gravitational waves
- Cosmology seeking friendship with sterile neutrinos
- Cosmological bounds on dark matter-neutrino interactions
- Limits on Dark Radiation, Early Dark Energy, and Relativistic Degrees of Freedom
- Observational bounds on the cosmic radiation density
- Dark Radiation Emerging After Big Bang Nucleosynthesis?
- Sterile Neutrinos in Light of Recent Cosmological and Oscillation Data: a Multi-Flavor Scheme Approach
- An improved cosmological bound on the thermal axion mass
- Are cosmological neutrinos free-streaming?
- Probing the Effective Number of Neutrino Species with Cosmic Microwave Background
- Anisotropies in the Cosmic Neutrino Background after WMAP 5-year Data
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- Sterile Neutrinos: Cosmology vs Short-BaseLine Experiments
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- Dark radiation from particle decay: cosmological constraints and opportunities
- Constraints on secret neutrino interactions after Planck
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- The two-mode puzzle: Confronting self-interacting neutrinos with the full shape of the galaxy power spectrum
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- Updating non-standard neutrinos properties with Planck-CMB data and full-shape analysis of BOSS and eBOSS galaxies
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- Origin of Delta N_eff as a Result of an Interaction between Dark Radiation and Dark Matter
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- Dark Radiation Confronting LHC in Z' Models
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