What will it take to measure individual neutrino mass states using cosmology?

Archidiacono, Maria; Hannestad, Steen; Lesgourgues, Julien

doi:10.48550/arxiv.2003.03354

Cited by 7 publications

(10 citation statements)

References 55 publications

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“…Hence, the presence of massive neutrinos can be detected in the CMB, as a change in the non-linear matter power spectrum traced by weak lensing and galaxy clustering, as a scaledependence in the growth rate of structure measured by galaxy clustering in redshift-space, and in the expansion history measured by e.g., BAO and supernovae. Consequently, the simplest ΛCDM scenario requires non-zero neutrino masses in order to satisfy the observations, but the impact of the individual mass values or their hierarchy is negligible [174]. It is therefore common (e.g.…”

Section: Neutrino Massesmentioning

confidence: 99%

CosmoBit: a GAMBIT module for computing cosmological observables and likelihoods

Workgroup¹,

Renk²,

Stöcker³

et al. 2021

J. Cosmol. Astropart. Phys.

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We introduce CosmoBit, a module within the open-source GAMBIT software framework for exploring connections between cosmology and particle physics with joint global fits. CosmoBit provides a flexible framework for studying various scenarios beyond ΛCDM, such as models of inflation, modifications of the effective number of relativistic degrees of freedom, exotic energy injection from annihilating or decaying dark matter, and variations of the properties of elementary particles such as neutrino masses and the lifetime of the neutron. Many observables and likelihoods in CosmoBit are computed via interfaces to AlterBBN, CLASS, DarkAges, MontePython, MultiModeCode, and plc. This makes it possible to apply a wide range of constraints from large-scale structure, Type Ia supernovae, Big Bang Nucleosynthesis and the cosmic microwave background. Parameter scans can be performed using the many different statistical sampling algorithms available within the GAMBIT framework, and results can be combined with calculations from other GAMBIT modules focused on particle physics and dark matter. We include extensive validation plots and a first application to scenarios with non-standard relativistic degrees of freedom and neutrino temperature, showing that the corresponding constraint on the sum of neutrino masses is much weaker than in the standard scenario.

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Section: Neutrino Massesmentioning

confidence: 99%

CosmoBit: a GAMBIT module for computing cosmological observables and likelihoods

Workgroup¹,

Renk²,

Stöcker³

et al. 2021

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

show abstract

“…Upcoming CMB experiments such as the Simons Observatory, LiteBIRD or CMB-S4 and large scale structure (LSS) experiments such as Euclid will allow us to fully constrain the sum of neutrino masses m ν . However, even under the most optimistic assumptions, it will not be possible to disentangle the individual contributions of the three neutrino flavours with cosmological data alone [16]. To achieve that, we need additional data from solar, atmospheric, reactor and accelerator experiments as summarised in NuFIT 5.0 (2020) [45,46] that provide us with the mass square splittings:…”

Section: Neutrino Massesmentioning

confidence: 99%

Bayesian evidence for the tensor-to-scalar ratio $r$ and neutrino masses $m_ν$: Effects of uniform vs logarithmic priors

Hergt,

Handley,

Hobson

et al. 2021

Preprint

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We review the effect that the choice of a uniform or logarithmic prior has on the Bayesian evidence and hence on Bayesian model comparisons when data provide only a one-sided bound on a parameter. We investigate two particular examples: the tensor-to-scalar ratio r of primordial perturbations and the mass of individual neutrinos mν , using the cosmic microwave background temperature and polarisation data from Planck 2018 and the NuFIT 5.0 data from neutrino oscillation experiments. We argue that the Kullback-Leibler divergence, also called the relative entropy, mathematically quantifies the Occam penalty. We further show how the Bayesian evidence stays invariant upon changing the lower prior bound of an upper constrained parameter. While a uniform prior on the tensor-to-scalar ratio disfavours the r-extension compared to the base ΛCDM model with odds of about 1 : 20, switching to a logarithmic prior renders both models essentially equally likely. ΛCDM with a single massive neutrino is favoured over an extension with variable neutrino masses with odds of 20 : 1 in case of a uniform prior on the lightest neutrino mass, which decreases to roughly 2 : 1 for a logarithmic prior. For both prior options we get only a very slight preference for the normal over the inverted neutrino hierarchy with Bayesian odds of about 3 : 2 at most.

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“…With the interplay of standard nuclear and particle physics and the standard cosmological model, it describes with great accuracy the synthesis of the lighter nuclei during the very first seconds of cosmic time (For a review see [50]). Despite some uncertainties on the predictions for 7 Li, which may have a diversity of possible sources [51,52], it predicts the observed relative abundances of H, D, 3 He, 4 He and 7 Li as a function of a single parameter, the baryon-to-photon ratio, η = n b /n γ , or equivalently, the present baryon density Ω b h 2 , which determines the end of the deuterium bottleneck, and therefore, the production rate of heavier nuclei.…”

Section: Bbn Constraintsmentioning

confidence: 99%

“…These are one order of magnitude better than those from experimental counterparts [5]. Cosmology now leads the race to determine the neutrino mass hierarchy, and possibly, measure the mass of at least one neutrino throughout this decade [6,7]. Moreover, three standard neutrinos are required to predict accurately the abundance of light elements on the Universe through big bang nucleosynthesis (BBN) [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Bounds on neutrino-scalar nonstandard interactions from big bang nucleosynthesis

Venzor,

Pérez-Lorenzana,

De-Santiago

2020

Preprint

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Coherent forward scattering processes by neutrino-scalar non-standard interactions (SNSI) induce an effective neutrino mass. In the Early Universe, a large neutrino effective mass restricts the production of neutrinos. The SNSI effect is modulated by two effective couplings, these account for the coupling between neutrinos and electrons/positrons, G eff , and the neutrino self-interaction, GS. These parameters are directly related to the effective number of relativistic species and nonzero values imply a smaller than expected N eff . We employ big bang nucleosynthesis to constraint the SNSI effect. We find that G eff < 3.8 MeV −2 and GS < 6.2 × 10 7 MeV −2 at 95% CL. For a scalar mass in the range 10 −15 eV m φ 10 −5 eV, our neutrino-scalar coupling constraint is more restrictive than any previous result.I.

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What will it take to measure individual neutrino mass states using cosmology?

Cited by 7 publications

References 55 publications

CosmoBit: a GAMBIT module for computing cosmological observables and likelihoods

CosmoBit: a GAMBIT module for computing cosmological observables and likelihoods

Bayesian evidence for the tensor-to-scalar ratio $r$ and neutrino masses $m_ν$: Effects of uniform vs logarithmic priors

Bounds on neutrino-scalar nonstandard interactions from big bang nucleosynthesis

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