6533b82cfe1ef96bd128f5b2
RESEARCH PRODUCT
How to relax the cosmological neutrino mass bound
Gabriela BarenboimSarah KahlenJordi SalvadoDominik J. SchwarzIsabel M. Oldengottsubject
Particle physicsCosmology and Nongalactic Astrophysics (astro-ph.CO)cosmological neutrinosPhysics::Instrumentation and DetectorsAstrophysics::High Energy Astrophysical PhenomenaCosmic microwave backgroundFOS: Physical sciencesAstrophysics::Cosmology and Extragalactic Astrophysicscosmological parameters from LSS01 natural sciencesCosmologyMomentumsymbols.namesakeHigh Energy Physics - Phenomenology (hep-ph)cosmological0103 physical sciencesPhysicsCOSMIC cancer database010308 nuclear & particles physicsMatter power spectrumHigh Energy Physics::Phenomenologycosmological parameters from CMBRAstronomy and AstrophysicsObservableMarkov chain Monte Carloneutrino masses from cosmologyHigh Energy Physics - Phenomenologyparameters from CMBRsymbolsHigh Energy Physics::ExperimentNeutrinoAstrophysics - Cosmology and Nongalactic Astrophysicsdescription
We study the impact of non-standard momentum distributions of cosmic neutrinos on the anisotropy spectrum of the cosmic microwave background and the matter power spectrum of the large scale structure. We show that the neutrino distribution has almost no unique observable imprint, as it is almost entirely degenerate with the effective number of neutrino flavours, $N_{\mathrm{eff}}$, and the neutrino mass, $m_{\nu}$. Performing a Markov chain Monte Carlo analysis with current cosmological data, we demonstrate that the neutrino mass bound heavily depends on the assumed momentum distribution of relic neutrinos. The message of this work is simple and has to our knowledge not been pointed out clearly before: Cosmology allows that neutrinos have larger masses if their average momentum is larger than that of a perfectly thermal distribution. Here we provide an example in which the mass limits are relaxed by a factor of two.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2019-01-14 |