Sum Of Neutrino Masses Research Articles

Towards unification of quark and lepton flavors in A_4 modular invariance

We study quark and lepton mass matrices in the A_4 modular symmetry towards the unification of the quark and lepton flavors. We adopt modular forms of weights 2 and 6 for quarks and charged leptons, while we use modular forms of weight 4 for the neutrino mass matrix which is generated by the Weinberg operator. We obtain the successful quark mass matrices, in which the down-type quark mass matrix is constructed by modular forms of weight 2, but the up-type quark mass matrix is constructed by modular forms of weight 6. The viable region of tau is close to tau =i. Lepton mass matrices also work well at nearby tau =i, which overlaps with the one of the quark sector, for the normal hierarchy of neutrino masses. In the common tau region for quarks and leptons, the predicted sum of neutrino masses is 87–120 meV taking account of its cosmological bound. Since both the Dirac CP phase delta _{CP}^ell and sin ^2theta _{23} are correlated with the sum of neutrino masses, improving its cosmological bound provides crucial tests for our scheme as well as the precise measurement of sin ^2theta _{23} and delta _{CP}^ell . The effective neutrino mass of the 0nu beta beta decay is langle m_{ee}rangle =15–31 meV. It is remarked that the modulus tau is fixed at nearby tau =i in the fundamental domain of SL(2, Z), which suggests the residual symmetry Z_2 in the quark and lepton mass matrices. The inverted hierarchy of neutrino masses is excluded by the cosmological bound of the sum of neutrino masses.

Starletℓ1-norm for weak lensing cosmology

We present a new summary statistic for weak lensing observables, higher than second order, suitable for extracting non-Gaussian cosmological information and inferring cosmological parameters. We name this statistic the ‘starletℓ1-norm’ as it is computed via the sum of the absolute values of the starlet (wavelet) decomposition coefficients of a weak lensing map. In comparison to the state-of-the-art higher-order statistics – weak lensing peak counts and minimum counts, or the combination of the two – theℓ1-norm provides a fast multi-scale calculation of the full void and peak distribution, avoiding the problem of defining what a peak is and what a void is: theℓ1-norm carries the information encoded in all pixels of the map, not just the ones in local maxima and minima. We show its potential by applying it to the weak lensing convergence maps provided by theMassiveNussimulations to get constraints on the sum of neutrino masses, the matter density parameter, and the amplitude of the primordial power spectrum. We find that, in an ideal setting without further systematics, the starletℓ1-norm remarkably outperforms commonly used summary statistics, such as the power spectrum or the combination of peak and void counts, in terms of constraining power, representing a promising new unified framework to simultaneously account for the information encoded in peak counts and voids. We find that the starletℓ1-norm outperforms the power spectrum by 72% onMν, 60% on Ωm, and 75% onAsfor theEuclid-like setting considered; it also improves upon the state-of-the-art combination of peaks and voids for a single smoothing scale by 24% onMν, 50% on Ωm, and 24% onAs.

Accurate analytic model for the weak lensing convergence one-point probability distribution function and its autocovariance

The one-point probability distribution function (PDF) is a powerful summary statistic for non-Gaussian cosmological fields, such as the weak lensing (WL) convergence reconstructed from galaxy shapes or cosmic microwave background (CMB) maps. Thus far, no analytic model has been developed that successfully describes the high-convergence tail of the WL convergence PDF for small smoothing scales from first principles. Here, we present a halo-model formalism to compute the WL convergence PDF, building upon our previous results for the thermal Sunyaev-Zel'dovich field. Furthermore, we extend our formalism to analytically compute the covariance matrix of the convergence PDF. Comparisons to numerical simulations generally confirm the validity of our formalism in the non-Gaussian, positive tail of the WL convergence PDF, but also reveal the convergence PDF's strong sensitivity to small-scale systematic effects in the simulations (e.g., due to finite resolution). Finally, we present a simple Fisher forecast for a Rubin-Observatory-like survey, based on our new analytic model. Considering the $\{A_s, \Omega_m, \Sigma m_\nu\}$ parameter space and assuming a Planck CMB prior on $A_s$ only, we forecast a marginalized constraint $\sigma(\Sigma m_\nu) \approx 0.08$ eV from the WL convergence PDF alone, even after marginalizing over parameters describing the halo concentration-mass relation. This error bar on the neutrino mass sum is comparable to the minimum value allowed in the normal hierarchy, illustrating the strong constraining power of the WL convergence PDF. We make our code publicly available at https://github.com/leanderthiele/hmpdf.

Standard Candles and Sirens Rescue H0

Abstract We show that future observations of binary neutron star systems with electromagnetic counterparts together with the traditional probes of low- and high-redshift Type Ia supernovae (SNe Ia) can help resolve the Hubble tension. The luminosity distance inferred from these probes and its scatter depend on the underlying cosmology. By using the gravitational lensing of light or gravitational waves emitted by, and peculiar motion of, these systems we derive constraints on the sum of neutrino masses, the equation of state of dark energy parameterized in the form , along with the Hubble constant and cold dark matter density in the universe. We show that even after marginalizing over poorly constrained physical quantities, such as the sum of neutrino masses and the nature of dark energy, low-redshift gravitational-wave observations, in combination with SNe Ia, have the potential to rule out new physics as the underlying cause of the Hubble tension at ≳5.5σ.

Constraining neutrino masses with weak-lensing multiscale peak counts

Massive neutrinos influence the background evolution of the Universe as well as the growth of structure. Being able to model this effect and constrain the sum of their masses is one of the key challenges in modern cosmology. Weak-lensing cosmological constraints will also soon reach higher levels of precision with next-generation surveys like LSST, WFIRST and Euclid. We use the MassiveNus simulations to derive constraints on the sum of neutrino masses $M_{\nu}$, the present-day total matter density $\Omega_{\rm m}$, and the primordial power spectrum normalization $A_{\rm s}$ in a tomographic setting. We measure the lensing power spectrum as second-order statistics along with peak counts as higher-order statistics on lensing convergence maps generated from the simulations. We investigate the impact of multiscale filtering approaches on cosmological parameters by employing a starlet (wavelet) filter and a concatenation of Gaussian filters. In both cases peak counts perform better than the power spectrum on the set of parameters [$M_{\nu}$, $\Omega_{\rm m}$, $A_{\rm s}$] respectively by 63$\%$, 40$\%$ and 72$\%$ when using a starlet filter and by 70$\%$, 40$\%$ and 77$\%$ when using a multiscale Gaussian. More importantly, we show that when using a multiscale approach, joining power spectrum and peaks does not add any relevant information over considering just the peaks alone. While both multiscale filters behave similarly, we find that with the starlet filter the majority of the information in the data covariance matrix is encoded in the diagonal elements; this can be an advantage when inverting the matrix, speeding up the numerical implementation.

Developing a unified pipeline for large-scale structure data analysis with angular power spectra – III. Implementing the multitracer technique to constrain neutrino masses

ABSTRACT In this paper, we apply the multitracer technique to harmonic-space (i.e. angular) power spectra with a likelihood-based approach. This goes beyond the usual Fisher matrix formalism hitherto implemented in forecasts with angular statistics, opening up a window for future developments and direct application to available data sets. We also release a fully operational modified version of the publicly available code CosmoSIS, where we consistently include all the add-ons presented in the previous papers of this series. The result is a modular cosmological parameter estimation suite for angular power spectra of galaxy number counts, allowing for single and multiple tracers, and including density fluctuations, redshift-space distortions, and weak-lensing magnification. We demonstrate the improvement on parameter constraints enabled by the use of multiple tracers on a multitracing analysis of luminous red galaxies and emission-line galaxies. We obtain an enhancement of $44{{\ \rm per\ cent}}$ on the 2σ upper bound on the sum of neutrino masses.

Dark energy and neutrino mass from a transient vacuum particle pair model

We propose that the transient vacuum fluctuations of quantum fields can be represented by transient vacuum quanta where both the lifetime and spatial extent are given by the Heisenberg Uncertainty Principle, HUP. Accordingly, a quantum field fluctuation at any spatial site results in the creation of a transient HUP-limited vacuum pair, corresponding to the particle and the antiparticle associated with that quantum field. All HUP-limited vacuum pairs, both massive and massless, are found to be on-shell particles, and are indistinguishable from each other except for differences related to their exchange symmetry. We find that the net vacuum energy density of all HUP-limited vacuum pairs is identically zero at any energy where both bosonic and fermionic transient vacuum pairs are present. The net vacuum energy density, from zero energy to the Planck limit, is found to be proportional to that of the rest mass of the lightest fermion, the lowest mass neutrino eigenstate. This net energy density is equal to the observed dark energy density if the mass of the lightest neutrino eigenstate is 3.2[Formula: see text]meV. The model predicts the absolute values of the masses of the three neutrino mass eigenstates and of the three neutrino flavor eigenstates for both normal and inverted ordering. The sum of the neutrino masses is found to be below the Planck satellite upper limit of 120[Formula: see text]meV, and the neutrino mass sum for normal ordering is below the most stringent upper bound of 78[Formula: see text]meV, indicating a preference for normal ordering.

Cornering (quasi) degenerate neutrinos with cosmology

In light of the improved sensitivities of cosmological observations, we examine the status of quasi-degenerate neutrino mass scenarios. Within the simplest extension of the standard cosmological model with massive neutrinos, we find that quasi-degenerate neutrinos are severely constrained by present cosmological data and neutrino oscillation experiments. We find that Planck 2018 observations of cosmic microwave background (CMB) anisotropies disfavour quasi-degenerate neutrino masses at 2.4 Gaussian σ’s, while adding baryon acoustic oscillations (BAO) data brings the rejection to 5.9σ’s. The highest statistical significance with which one would be able to rule out quasi-degeneracy would arise if the sum of neutrino masses is ∑mv = 60 meV (the minimum allowed by neutrino oscillation experiments); indeed a sensitivity of 15 meV, as expected from a combination of future cosmological probes, would further improve the rejection level up to 17σ. We discuss the robustness of these projections with respect to assumptions on the underlying cosmological model, and also compare them with bounds from β decay endpoint and neutrinoless double beta decay studies.

Improvements in cosmological constraints from breaking growth degeneracy

Context. The key probes of the growth of a large-scale structure are its rate f and amplitude σ8. Redshift space distortions in the galaxy power spectrum allow us to measure only the combination fσ8, which can be used to constrain the standard cosmological model or alternatives. By using measurements of the galaxy-galaxy lensing cross-correlation spectrum or of the galaxy bispectrum, it is possible to break the fσ8 degeneracy and obtain separate estimates of f and σ8 from the same galaxy sample. Currently there are very few such separate measurements, but even this allows for improved constraints on cosmological models. Aims. We explore how having a larger and more precise sample of such measurements in the future could constrain further cosmological models. Methods. We considered what can be achieved by a future nominal sample that delivers an ∼1% constraint on f and σ8 separately, compared to the case with a similar precision on the combination fσ8. Results. For the six cosmological parameters of ΛCDM, we find improvements of ∼5–50% on their constraints. For modified gravity models in the Horndeski class, the improvements on these standard parameters are ∼0–15%. However, the precision on the sum of neutrino masses improves by 65% and there is a significant increase in the precision on the background and perturbation Horndeski parameters.

Update constraints on neutrino mass and mass hierarchy in light of dark energy models

Combining cosmic microwave (CMB) background data from Planck satellite data, Baryon Acoustic Oscillations (BAO) measurements and Type Ia supernovae (SNe Ia) data, we obtain the bounds on total neutrino masses [Formula: see text] with the approximation of degenerate neutrino masses and for three dark energy models: the cosmological constant ([Formula: see text]CDM) model, a phenomenological emergent dark energy (PEDE) model and a model-independent quintessential parametrization (HBK). The bounds on the sum of neutrino masses [Formula: see text] depend on the dark energy (DE) models. In the HBK model, we confirm the conclusion from some previous work that the quintessence prior of DE tends to tighten the cosmological constraint on [Formula: see text]. On the other hand, the PEDE model leads to larger [Formula: see text] and a nonzero lower bound. Besides, we also explore the correlation between three different neutrino hierarchies and DE models.

Extended reionization in models beyond ΛCDM with Planck 2018 data

We provide an update on the constraints on extended reionization histories with the Planck 2018 cosmic microwave background anisotropy data. The Planck 2018 data on large angular scales improve the measurement of the E-mode polarization reionization bump at low multipoles providing the possibility to improve our previous results [1]. Using a minor modification to the original Poly-reion model [2] for the reionization history, we find that the Planck 2018 data significantly improve all our previous results: we find as optical depth of τ=0.0572−0.0075+0.0064 at 68% CL, that early onsets of reionization are strongly disfavoured, i.e. redshift when the reionization begins, zxe=0=18.18−10.89 +1.61 at 68% CL, and that reionization duration (defined between 10% and 99% reionization) is significantly reduced, i.e. ΔzReion=4.59−2.45+1.67 at 68% CL . We explore possible correlations between reionization histories and cosmological parameters, including important extensions beyond ΛCDM . We find that the degeneracy between reionization and scalar spectral index, neutrino mass sum, spatial curvature, dark matter annihilation and other non-standard models are significantly reduced.The reduction of the error bars and the degeneracies, together with the shift towards lower values of the optical depth that we observe in the Poly-reion model are mainly driven by the new low-ℓ polarization likelihood of Planck 2018 baseline based on the HFI data. This is confirmed also by the results derived without this likelihood and the ones with different alternatives to the baseline that are presented for a subset of models.

Predictive Dirac and Majorana neutrino mass textures from SU(6) grand unified theories

We present simple and predictive realizations of neutrino masses in theories based on the $SU(6)$ grand unifying group. At the level of the lowest-dimension operators, this class of models predicts a skew-symmetric flavor structure for the Dirac mass term of the neutrinos. In the case that neutrinos are Dirac particles, the lowest-order prediction of this construction is then one massless neutrino and two degenerate massive neutrinos. Higher-dimensional operators suppressed by the Planck scale perturb this spectrum, allowing a good fit to the observed neutrino mass matrix. A firm prediction of this construction is an inverted neutrino mass spectrum with the lightest neutrino hierarchically lighter than the other two, so that the sum of neutrino masses lies close to the lower bound for an inverted hierarchy. In the alternate case that neutrinos are Majorana particles, the mass spectrum can be either normal or inverted. However, the lightest neutrino is once again hierarchically lighter than the other two, so that the sum of neutrino masses is predicted to lie close to the corresponding lower bound for the normal or inverted hierarchy. Near future cosmological measurements will be able to test the predictions of this scenario for the sum of neutrino masses. In the case of Majorana neutrinos that exhibit an inverted hierarchy, future neutrinoless double beta experiments can provide a complementary probe.

Running vacuum model in a non-flat universe * * Supported in part by National Center for Theoretical Sciences, MoST (MoST-107-2119-M-007-013-MY3), National Natural Science Foundation of China (11505004, 11447104) and the Anhui Provincial Natural Science Foundation of China (1508085QA17)

We investigate observational constraints on the running vacuum model (RVM) of in a spatially curved universe, where is the model parameter, corresponds to the spatial curvature constant, represents the scalar factor, and is a constant defined by the boundary conditions. We study the CMB power spectra with several sets of and in the RVM. By fitting the cosmological data, we find that the best fitted value for RVM is slightly smaller than that of CDM in the non-flat universe, along with the constraints of (68% C.L.) and (95% C.L.). In particular, our results favor the open universe in both CDM and RVM. In addition, we show that the cosmological constraints of (RVM) and ( CDM) at 95% C.L. for the neutrino mass sum are relaxed in both models in the spatially curved universe.

CMB distance priors revisited: effects of dark energy dynamics, spatial curvature, primordial power spectrum, and neutrino parameters

As a physical and sufficient compression of the full CMB data, the CMB distance priors, or shift parameters, have been widely used and provide a convenient way to include CMB data when obtaining cosmological constraints. In this paper, we revisit this data vector and examine its stability under different cosmological models. We find that the CMB distance priors are an accurate substitute for the full CMB data when probing dark energy dynamics. This is true when the primordial power spectrum model is directly generalized from the power spectrum of the model used in the derivation of the distance priors from the CMB data. We discover a difference when a non-flat model with the untilted primordial inflation power spectrum is used to measure the distance priors. This power spectrum is a radical change from the more conventional tilted primordial power spectrum and violates fundamental assumptions for the reliability of the CMB shift parameters. We also investigate the performance of CMB distance priors when the sum of neutrino masses ∑ mν and the effective number of relativistic species Neff are allowed to vary. Our findings are consistent with earlier results: the neutrino parameters can change the measurement of the sound horizon from CMB data, and thus the CMB distance priors. We find that when the neutrino model is allowed to vary, the cold dark matter density ωc and Neff need to be included in the set of parameters that summarize CMB data, in order to reproduce the constraints from the full CMB data. We present an updated and expanded set of CMB distance priors which can reproduce constraints from the full CMB data within 1σ, and are applicable to models with massive neutrinos, as well as non-standard cosmologies.

U(1)B−3Lα extended scotogenic models and single-zero textures of neutrino mass matrices

In this paper, we propose a scotogenic model of neutrino masses with flavor-dependent $U(1)_{B-3L_\alpha}(\alpha=e, \mu, \tau)$ gauge symmetry, in which neutrinos are generated at one-loop level and a fermion dark matter is naturally accommodated. In this model, three one-zero-texture structures of neutrino mass matrix, denoted as patterns A, B and C, are successfully realized by appropriate charge assignment for inert fermions and scalar fields. For each predicted textures, a detailed numerical analysis is carried out to find the allowed regions of neutrino mixing and masses. We find three scenarios (A for normal mass hierarchy, and B and C for inverted mass hierarchy) favored by the latest data of neutrino oscillation experiments and Planck 2018 limit on the sum of neutrino masses. Other phenomenologies such as lepton flavor violation, dark matter and collider signatures are also discussed.

Addendum to “Global constraints on absolute neutrino masses and their ordering”

We revisit our previous work [Phys. Rev. D 95, 096014 (2017)] where neutrino oscillation and nonoscillation data were analyzed in the standard framework with three neutrino families, in order to constrain their absolute masses and to probe their ordering (either normal, NO, or inverted, IO). We include updated oscillation results to discuss best fits and allowed ranges for the two squared mass differences $\delta m^2$ and $\Delta m^2$, the three mixing angles $\theta_{12}$, $\theta_{23}$ and $\theta_{13}$, as well as constraints on the CP-violating phase $\delta$, plus significant indications in favor of NO vs IO at the level of $\Delta\chi^2=10.0$. We then consider nonoscillation data from beta decay, from neutrinoless double beta decay (if neutrinos are Majorana), and from various cosmological input variants (in the data or the model) leading to results dubbed as default, aggressive, and conservative. In the default option, we obtain from nonoscillation data an extra contribution $\Delta\chi^2 = 2.2$ in favor of NO, and an upper bound on the sum of neutrino masses $\Sigma < 0.15$ eV at $2\sigma$; both results - dominated by cosmology - can be strengthened or weakened by using more aggressive or conservative options, respectively. Taking into account such variations, we find that the combination of all (oscillation and nonoscillation) neutrino data favors NO at the level of $3.2-3.7\sigma$, and that $\Sigma$ is constrained at the $2\sigma$ level within $\Sigma < 0.12-0.69$ eV. The upper edge of this allowed range corresponds to an effective $\beta$-decay neutrino mass $m_\beta = \Sigma/3 = 0.23$ eV, at the sensitivity frontier of the KATRIN experiment.

Neutrino puzzle: Anomalies, interactions, and cosmological tensions

New physics in the neutrino sector might be necessary to address anomalies between different neutrino oscillation experiments. Intriguingly, it also offers a possible solution to the discrepant cosmological measurements of $H_0$ and $\sigma_8$. We show here that delaying the onset of neutrino free-streaming until close to the epoch of matter-radiation equality can naturally accommodate a larger value for the Hubble constant $H_0=72.3 \pm 1.4$ km/s/Mpc and a lower value of the matter fluctuations $\sigma_8=0.786\pm 0.020$, while not degrading the fit to the cosmic microwave background (CMB) damping tail. We achieve this by introducing neutrino self-interactions in the presence of a non-vanishing sum of neutrino masses. This strongly interacting neutrino cosmology prefers $N_{\rm eff} = 4.02 \pm 0.29$, which has interesting implications for particle model-building and neutrino oscillation anomalies. We show that the absence of the neutrino free-streaming phase shift on the CMB can be compensated by shifting the value of other cosmological parameters, hence providing an important caveat to the detections made in the literature. Due to their impact on the evolution of the gravitational potential at early times, self-interacting neutrinos and their subsequent decoupling leave a rich structure on the matter power spectrum. In particular, we point out the existence of a novel localized feature appearing on scales entering the horizon at the onset of neutrino free-streaming. While the interacting neutrino cosmology provides a better global fit to current cosmological data, we find that traditional Bayesian analyses penalize the model as compared to the standard cosmological. Our analysis shows that it is possible to find radically different cosmological models that nonetheless provide excellent fits to the data, hence providing an impetus to thoroughly explore alternate cosmological scenarios.

Efficient cosmological analysis of the SDSS/BOSS data from the Effective Field Theory of Large-Scale Structure

The precision of the cosmological data allows us to accurately approximate the predictions for cosmological observables by Taylor expanding up to a low order the dependence on the cosmological parameters around a reference cosmology. By applying this observation to the redshift-space one-loop galaxy power spectrum of the Effective Field Theory of Large-Scale Structure, we analyze the BOSS DR12 data by scanning over all the parameters of ΛCDM cosmology with massive neutrinos. We impose several sets of priors, the widest of which is just a Big Bang Nucleosynthesis prior on the current fractional energy density of baryons, Ωb h2, and a bound on the sum of neutrino masses to be less than 0.9 eV. In this case we measure the primordial amplitude of the power spectrum, As, the abundance of matter, Ωm, the Hubble parameter, H0, and the tilt of the primordial power spectrum, ns, to about 19%, 5.7%, 2.2% and 7.3% respectively, obtaining ln (1010As)=2.91± 0.19, Ωm=0.314± 0.018, H0=68.7± 1.5 km/(s Mpc) and ns=0.979± 0.071 at 68% confidence level. A public code is released with this preprint.

Exploring early and late cosmology with next generation surveys

Perturbations from inflation evolve into large scale structure of the late universe, and encode abundant cosmic structure formation physics. We allow freedom in the primordial power spectrum, rather than assuming a power law scale dependence, to study its impact on cosmological parameter determination. Combining various generations of cosmic microwave background (CMB) data and galaxy redshift survey data, we investigate the constraints on reconstruction of the primordial curvature perturbation power spectrum and the late time cosmology, especially the sum of neutrino masses. We quantify how each successive generation, in CMB and galaxy surveys, provides significant improvements, often by factors of several. By using CMB polarization information over a broad range of angular scales, and galaxy redshift data in many bins of redshift, one can allow inflationary freedom and still constrain parameters comparably to assuming power law dependence. The primordial power spectrum can be reconstructed at the subpercent level in a dozen wavenumber bins, while simultaneously fitting the sum of neutrino masses to 14 meV.

Combining full-shape and BAO analyses of galaxy power spectra: a 1.6% CMB-independent constraint on H0

We present cosmological constraints from a joint analysis of the pre- and post-reconstruction galaxy power spectrum multipoles from the final data release of the Baryon Oscillation Spectroscopic Survey (BOSS). Geometric constraints are obtained from the positions of BAO peaks in reconstructed spectra, which are analyzed in combination with the unreconstructed spectra in a full-shape (FS) likelihood using a joint covariance matrix, giving stronger parameter constraints than FS-only or BAO-only analyses. We introduce a new method for obtaining constraints from reconstructed spectra based on a correlated theoretical error, which is shown to be simple, robust, and applicable to any flavor of density-field reconstruction. Assuming ΛCDM with massive neutrinos, we analyze clustering data from two redshift bins zeff=0.38,0.61 and obtain 1.6% constraints on the Hubble constant H0, using only a single prior on the current baryon density ωb from Big Bang Nucleosynthesis (BBN) and no knowledge of the power spectrum slope ns. This gives H0 = 68.6±1.1 km s−1Mpc−1, with the inclusion of BAO data sharpening the measurement by 40%, representing one of the strongest current constraints on H0 independent of cosmic microwave background data, comparable with recent constraints using BAO data in combination with other data-sets. Restricting to the best-fit slope ns from Planck (but without additional priors on the spectral shape), we obtain a 1% H0 measurement of 67.8± 0.7 km s−1Mpc−1. Finally, we find strong constraints on the cosmological parameters from a joint analysis of the FS, BAO, and Planck data. This sets new bounds on the sum of neutrino masses ∑ mν < 0.14 eV (at 95% confidence) and the effective number of relativistic degrees of freedom Neff = 2.90+0.15−0.16, though contours are not appreciably narrowed by the inclusion of BAO data.