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Probing Unstable Massive Neutrinos with Current Cosmic Microwave Background Observations

Robert E. Lopez·Scott Dodelson·Robert J. Scherrer·Michael S. Turner
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Abstract

The pattern of anisotropies in the Cosmic Microwave Background depends upon the masses and lifetimes of the three neutrino species. A neutrino species of mass greater than 10 eV with lifetime between 10^{13} sec and 10^{17} sec leaves a very distinct signature (due to the integrated Sachs-Wolfe effect): the anisotropies at large angles are predicted to be comparable to those on degree scales. Present data exclude such a possibility and hence this region of parameter space. For $m_ν\simeq 30$ eV, $τ\simeq 10^{13}$ sec, we find an interesting possibility: the Integrated Sachs Wolfe peak produced by the decaying neutrino in low-$Ω$ models mimics the acoustic peak expected in an $Ω= 1$ model.

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Robert E. Lopez, Scott Dodelson, Robert J. Scherrer, Michael S. Turner. 1998-06-08. Probing Unstable Massive Neutrinos with Current Cosmic Microwave Background Observations. https://doi.org/10.1103/physrevlett.81.3075

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