Invited Talk at Identification of Dark Matter 2010-IDM2010, July 26-30, 2010, Montpellier France. This paper has been temporarily withdrawn until it receives approval from the Planck Editorial Board
After reviewing the main mechanisms by which cosmological measurements constrain the sum of neutrino masses, I give the current reached upper limits, emphasizing the level of model-dependence. A large improvement is to be expected with PLANCK's satellite data, on which I give some news, in particular due to the characterization of the CMB-lensing effect. It will however require a thorough control of many systematics effects upon which progress has been made recently.
We investigate two dark energy cosmological models (i.e., the $Λ$CDM and $ϕ$CDM models) with massive neutrinos assuming two different neutrino mass hierarchies in both the spatially flat and non-flat scenarios, where in the $ϕ$CDM model the scalar field possesses an inverse power-law potential, $V(ϕ)\propto ϕ^{-α}$ ($α>0$). Cosmic microwave background data from Planck 2015, baryon acoustic oscillations data from 6dFGS, SDSS-MGS, BOSS-LOWZ and BOSS CMASS-DR11, the JLA compilation of Type Ia supernova apparent magnitude observations, and the Hubble Space Telescope $H_0$ prior, are jointly employ…
The Ly-$α$ forest 1D flux power spectrum is a powerful probe of several cosmological parameters. Assuming a $Λ$CDM cosmology including massive neutrinos, we find that the latest SDSS DR14 BOSS and eBOSS Ly-$α$ forest data is in very good agreement with current weak lensing constraints on $(Ω_m, σ_8)$ and has the same small level of tension with Planck. We did not identify a systematic effect in the data analysis that could explain this small tension, but we show that it can be reduced in extended cosmological models where the spectral index is not the same on the very different times and scale…
Both particle physics experiments and cosmological surveys can constrain the properties of sterile neutrinos, but do so with different parameterizations that naturally use different prior information. We present joint constraints on the 3$+$1 sterile neutrino model oscillation parameters, $Δm_{41}^2$ and $\sin^22θ$, with log priors on those parameters using mostly cosmological data from the Planck satellite. Two cases are considered, one where the sterile neutrino mixes with electron neutrinos solely, and another where the sterile neutrino mixes exclusively with muon neutrinos, allowing us to …
We consistently include the effect of massive neutrinos in the thermal Sunyaev Zeldovich (SZ) power spectrum and cluster counts analyses, highlighting subtle dependencies on the total neutrino mass and data combination. In particular, we find that using the transfer functions for Cold Dark Matter (CDM) + baryons in the computation of the halo mass function, instead of the transfer functions including neutrino perturbations, as prescribed in recent work, yields a $\approx$ 0.25\% downward shift of the $σ_8$ constraint from tSZ power spectrum data, with a fiducial neutrino mass $Σm_ν=0.06$ eV. I…
The strongest bounds on active-sterile neutrino mixing after Planck data
在早期宇宙中，活跃中微子的振荡可以激发出轻的惰性中微子。它们的性质可以通过它们作为额外辐射的贡献来限制，这些额外辐射可以用中微子种类的有效数量N_ eff和今天的宇宙能量密度Ω_ν h ^2来参数化。这两个参数都已通过普朗克卫星实验测量到相当高的精度。我们用这个结果来更新（3+1）无菌中微子情形的参数空间的边界，其中活性-无菌中微子的质量平方分裂在（10^{-5}-10^2）eV ^2范围内。我们认为正常和倒置的质量排序的活跃和不育状态。第一次，我们考虑到两个非零的积极-无菌混合角的可能性。我们发现，边界是更严格的比在实验室实验中得到的。这导致了与轻无菌中微子的短基线暗示的强烈张力。为了消除这种分歧，需要修改标准宇宙学的假设，例如大的原始中微子不对称性。
In recent years, the amplitude of matter fluctuations inferred from low-redshift probes has been found to be generally lower than the value derived from CMB observations in the $Λ$CDM model. This tension has been exemplified by Sunyaev-Zel'dovich and X-ray cluster counts which, when using their Planck standard cluster mass calibration, yield a value of $σ_8$ , appreciably lower than estimations based on the latest Planck CMB measurements. In this work we examine whether non-minimal neutrino masses can alleviate this tension substantially. We used the cluster X-ray temperature distribution func…
We reassess the viability of a cosmological model including a fourth additional sterile neutrino species that self-interacts through a new pseudoscalar degree of freedom. We perform a series of extensive analyses fitting various combinations of cosmic microwave background (CMB) data from Planck, the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT), both alone and in combination with Baryon Acoustic Oscillation (BAO) and Supernova Ia (SnIa) observations. We show that the scenario under study, although capable to resolve the Hubble tension without worsening the so-called $S_8…
We investigate a well known scenario of interaction in the dark sector where the vacuum energy is interacting with cold dark matter throughout the cosmic evolution in light of the cosmic microwave background (CMB) data from final Planck 2018 release. In addition to this minimal scenario, we generalize the model baseline by including the properties of neutrinos, such as the neutrino mass scale ($M_ν$) and the effective number of neutrino species ($N_{\rm eff}$) as free parameters, in order to verify the possible effects that such parameters might generate on the coupling parameter, and vice ver…
We examine a framework with light new physics, which couples to the Standard Model only via neutrino mixing. Taking the hints from the short-baseline anomalies seriously and combining them with modern cosmological data and recent IceCube measurements, we obtain surprisingly effective constraints on the hidden force: keV $\lesssim M \lesssim0.3$ GeV for the mediator mass and $g_{h}>10^{-6}-10^{-3}$ for the coupling constant. Flavor equilibration between the hidden and active neutrinos can be delayed until temperatures of $\sim 1$ MeV, but not below $\sim 100$ keV. This scenario can be tested wi…
Neutrinos are expected to freestream (i.e. not interact with anything) since they decouple in the early Universe at a temperature $T\sim 2~{\rm MeV}$. However, there are many relevant particle physics scenarios that can make neutrinos interact at $T< 2~{\rm MeV}$. In this work, we take a global perspective and aim to identify the temperature range in which neutrinos can interact given current cosmological observations. We consider a generic set of rates parametrizing neutrino interactions and by performing a full Planck cosmic microwave background (CMB) analysis we find that neutrinos cannot i…
We perform a comparative analysis of constraints on sterile neutrinos from the Planck experiment and from current and future neutrino oscillation experiments (MINOS, IceCube, SBN). For the first time, we express the Planck constraints on $N_{\rm eff}$ and $m_{\rm eff}^{\rm sterile}$ from the Cosmic Microwave Background in the parameter space used by oscillation experiments using both mass-squared differences and mixing angles. In a model with a single sterile neutrino species and using standard assumptions, we find that the Planck data and the oscillation experiments measuring muon-neutrino di…
We study a discrete flavour symmetric scenario for neutrino mass and dark matter under the circumstances where such global discrete symmetries can be explicitly broken at Planck scale, possibly by gravitational effects. Such explicit breaking of discrete symmetries mimic as Planck suppressed operators in the model which can have non-trivial consequences for neutrino and dark matter sectors. In particular, we study a flavour symmetric model which, at renormalisable level, gives rise to tri-bimaximal type neutrino mixing with vanishing reactor mixing angle $θ_{13}=0$, a stable inert scalar doubl…
We use $Planck$ 2018 data to constrain the simplest models of scalar-tensor theories characterized by a coupling to the Ricci scalar of the type $F(σ) R$ with $F(σ) = N_{pl}^2 + ξσ^2$. We update our results with previous $Planck$ and BAO data releases obtaining the tightest constraints to date on the coupling parameters, that is $ξ< 5.5 \times 10^{-4}$ for $N_{pl}=0$ (induced gravity or equivalently extended Jordan-Brans-Dicke) and $(N_{pl} \sqrt{8 πG})-1 < 1.8 \times 10^{-5}$ for $ξ= -1/6$ (conformal coupling), both at 95% CL. Because of a modified expansion history after radiation-matter equ…
We search for sterile neutrinos in the holographic dark energy cosmology by using the latest observational data. To perform the analysis, we employ the current cosmological observations, including the cosmic microwave background temperature power spectrum data from the Planck mission, the baryon acoustic oscillation measurements, the type Ia supernova data, the redshift space distortion measurements, the shear data of weak lensing observation, the Planck lensing measurement, and the latest direct measurement of $H_0$ as well. We show that, compared to the $Λ$CDM cosmology, the holographic dark…
Considering the mass splittings of three active neutrinos, we investigate how the nature of dark energy affects the cosmological constraints on the total neutrino mass $\sum m_ν$ using the latest cosmological observations. In this paper, some typical dark energy models, including $Λ$CDM, $w$CDM, CPL, and HDE models, are discussed. In the analysis, we also consider the effects from the neutrino mass hierarchies, i.e., the degenerate hierarchy (DH), the normal hierarchy (NH), and the inverted hierarchy (IH). We employ the current cosmological observations to do the analysis, including the Planck…
We present cosmological constraints from the combination of the full mission 9-year WMAP release and small-scale temperature data from the pre-Planck ACT and SPT generation of instruments. This is an update of the analysis presented in Calabrese et al. 2013 and highlights the impact on $Λ$CDM cosmology of a 0.06 eV massive neutrino - which was assumed in the Planck analysis but not in the ACT/SPT analyses - and a Planck-cleaned measurement of the optical depth to reionization. We show that cosmological constraints are now strong enough that small differences in assumptions about reionization a…
We investigate how dark energy properties impact the cosmological limits on the total mass of active neutrinos. We consider two typical, simple dark energy models (that have only one more additional parameter than $Λ$CDM), i.e., the $w$CDM model and the holographic dark energy (HDE) model, as examples, to make an analysis. In the cosmological fits, we use the Planck 2015 temperature and polarization data, in combination with other low-redshift observations, including the baryon acoustic oscillations, type Ia supernovae, and Hubble constant measurement, as well as the Planck lensing measurement…
Sterile neutrinos can affect the evolution of the universe, and thus using the cosmological observations can search for sterile neutrinos. In this work, we use the cosmic microwave background (CMB) anisotropy data from the Planck 2018 release, combined with the latest baryon acoustic oscillation (BAO), type Ia supernova (SN), and Hubble constant ($H_0$) data, to constrain the cosmological models with considering sterile neutrinos. In order to test the influences of the properties of dark energy on the {results} of searching for sterile neutrinos, in addition to the $Λ$ cold dark matter ($Λ$CDM…
We present a joint analysis of the Planck cosmic microwave background (CMB) and Baryon Oscillation Spectroscopic Survey (BOSS) final data releases. A key novelty of our study is the use of a new full-shape (FS) likelihood for the redshift-space galaxy power spectrum of the BOSS data, based on an improved perturbation theory template. We show that the addition of the redshift space galaxy clustering measurements breaks degeneracies present in the CMB data alone and tightens constraints on cosmological parameters. Assuming the minimal $Λ$CDM cosmology with massive neutrinos, we find the followin…
Secret contact interactions among eV sterile neutrinos, mediated by a massive gauge boson $X$ (with $M_X \ll M_W$), and characterized by a gauge coupling $g_X$, have been proposed as a mean to reconcile cosmological observations and short-baseline laboratory anomalies. We constrain this scenario using the latest Planck data on Cosmic Microwave Background anisotropies, and measurements of baryon acoustic oscillations (BAO). We consistently include the effect of secret interactions on cosmological perturbations, namely the increased density and pressure fluctuations in the neutrino fluid, and st…
Recent Cosmic Microwave Background (CMB) temperature and polarization anisotropy measurements from the Planck mission have significantly improved previous constraints on the neutrino masses as well as the bounds on extended models with massless or massive sterile neutrino states. However, due to parameter degeneracies, additional low redshift priors are mandatory in order to sharpen the CMB neutrino bounds. We explore here the role of different priors on low redshift quantities, such as the Hubble constant, the cluster mass bias, and the reionization optical depth $τ$. Concerning current prior…
We present a quantitative, direct comparison of constraints on sterile neutrinos derived from neutrino oscillation experiments and from Planck data, interpreted assuming standard cosmological evolution. We extend a $1+1$ model, which is used to compare exclusions contours at the 95% CL derived from Planck data to those from $ν_{e}$-disappearance measurements, to a $3+1$ model. This allows us to compare the Planck constraints with those obtained through $ν_μ\rightarrowν_{e}$ appearance searches, which are sensitive to more than one active-sterile mixing angle. We find that the cosmological data…
Using the latest observational data from Planck-CMB and its combination with the pre-reconstructed full-shape (FS) galaxy power spectrum measurements from the BOSS DR12 sample and eBOSS LRG DR16 sample, we report the observational constraints on the cosmic neutrino properties given by the extended $Λ$CDM scenario: $Λ$CDM + $N_{\rm eff}$ + $\sum m_ν$ + $c^2_{\rm eff}$ + $c^2_{\rm vis}$ + $ξ_ν$, and its particular case $Λ$CDM + $c^2_{\rm eff}$ + $c^2_{\rm vis}$ + $ξ_ν$, where $N_{\rm eff}$, $\sum m_ν$, $c^2_{\rm eff}$, $c^2_{\rm vis}$, $ξ_ν$ are the effective number of species, the total neutrin…
The impact of dark matter-neutrino interactions on the measurement of the cosmological parameters has been investigated in the past in the context of massless neutrinos exclusively. Here we revisit the role of a neutrino-dark matter coupling in light of ongoing cosmological tensions by implementing the full Boltzmann hierarchy for three massive neutrinos. Our tightest 95% CL upper limit on the strength of the interactions, parameterized via $u_χ=\frac{σ_0}{σ_{Th}}\left(\frac{m_χ}{100 \text{GeV}}\right)^{-1}$, is $u_χ\leq3.34 \cdot 10^{-4}$, arising from a combination of Planck TTTEEE data, Pla…
Nonstandard self-interactions can alter the evolution of cosmological neutrinos, mainly by damping free streaming, which should leave traces in cosmological observables. Although overall effects are opposite to those produced by neutrino mass and a larger $N_{\rm eff}$, they cannot be totally canceled by these last. We harness cosmological data that includes Cosmic Microwave Background from Plank 2018, BAO measurements, local $H_0$, Ly-$α$ and SNIa, to constrain massive neutrino self-interactions with a very light scalar mediator. We find that the effective coupling constant, at the 95\% C.L.,…
Following up on our earlier work predicting fractionally charged supermassive gravitinos, we explain their potential relevance as novel candidates for Dark Matter and discuss possible signatures and ways to detect them.
