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Relic Neutrinos , thermal axions and cosmology in early 2014

Relic Neutrinos , thermal axions and cosmology in early 2014 . Elena Giusarma. arXiv:1403.4852. Based on work in collaboration with: E. Di Valentino, M. Lattanzi, A. Melchiorri, O. Mena. Outline . Cosmological neutrino mass implications

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Relic Neutrinos , thermal axions and cosmology in early 2014

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  1. RelicNeutrinos, thermalaxions and cosmology in early 2014 Elena Giusarma arXiv:1403.4852 Based on work in collaboration with: E. Di Valentino, M. Lattanzi, A. Melchiorri, O. Mena

  2. Outline • Cosmological neutrino massimplications • Existence of extra hotreliccomponents as darkradiationrelics, steriles neutrino species and/orthermalaxions • Cosmological data used in ournumericalanalysis • Neutrino massbounds in differentcosmologicalscenarios • Impact of BICEP2 measurementsfortherelativisitcdegrees of freedom and neutrino masses • Conclusions

  3. In thestanardcosmologyhot, thermalrelics are identifiedwiththethree light, active neutrino flavours of the Standard Model of elementary particles. • Neutrino masses have an impact in the different cosmological observable: • CMB: a) Early Integrated Sachs Wolfe effect. The transition from the relativistic to the non relativistic neutrino regime affect the decays of the gravitational potentials at decoupling period (especially near the first acoustic peak). b) Suppression of lensing potential (with Planck). • LSS: Suppression of structure formation on scales smaller than the free streaming scale when neutrinos turn non relativistic. Planck+WMAP 9-polarization data: ∑mν <1.11 eV at 95% CL Planck+WMAP 9-polarization +HST data: ∑mν <0.21 eV at 95% CL Planck+WMAP 9-polarization +HST+BAO data: ∑mν <0.26 eV at 95% CL (M. Tegmark) (Ade et al ‘13 Planck Collaboration )

  4. Candidates for extra hot relic components • Massless sterile neutrino species: e.g. extra degrees of freedom produced by the annihilation of asymmetric Dark Matter • Extra sterilesmassive neutrino species: motivated by the so-called neutrino oscillation anomalies • Thermal axion: motivated by the strong CP problem These extra species Contribute to the effectivenumber of relativisticdegrees of freedomNeff Have an associated free streaming scales, reducing the growth of matterfluctuationsat small scales Neff= 3.046+ΔNeff

  5. Data1 • CMB: • Planck temperature anisotropies, includinglensingpotential • WMAP 9-year polarization • ACT and SPT measurements at small scales • B-mode polarizationmeasurements from BICEP2 • Large scale structure: • SDSS Data Release 7 • 6-degree Field GalaxySurvey • New BOSS Data Release 11 • WiggleZsurvey (the full shape of the matterpowerspectrum and the geometrical BAO information ) BaryonAcousticOscillation (BAO) data

  6. Data2 • Hubble constant measurements: • Hubble Space Telescope • σ8 measurements: • CFHTLenssurvey • PlanckSunyaev-Zeldovich cluster catalog • Big Bang Nucleosynthesis light elements abundance:

  7. Cosmologicalparameters ΛCDM model with 3 massive neutrino species: 2. ΛCDM model with 3 massive neutrino species and thermalaxion: Extra Radiation Component at the BBN period 3. ΛCDM model with 3 massive neutrino and ΔNeffmasslessdarkradiationspecies:

  8. Cosmologicalparameters 4. ΛCDMmodel with 3 active massive neutrinos plus ΔNeff massive steriles neutrino species: Ts, Tνcurrent temperature of the sterile and active neutrino species. msreal mass of sterile neutrinospecies. ΔNeff=Neff-3.46=(Ts /Tν)4 UNIFORM PRIORS for the cosmological parameters: Neffpriorsrefertothemassless (massive) case

  9. MainResults(1) ΛCDM model with 3 massive neutrino species: 68% and 95% CL allowedregions in the (∑mν,H0) and in the (∑mν, σ8) plane The allowed neutrino mass regions are displaced after considering Planck cluster data and a non zero value on ∑mνisfavoured. Giusarma et al arXiv:1403.4852 CMB+DR11+BAO+HST: CMB+DR11+BAO+HST+SZ Cluster: CMB+DR11+BAO+HST+CFHTLens: The addition of the constraints on σ8andΩmfrom the CFHTLens survey displaces the bounds on the neutrino mass to higher values.

  10. MainResults(2) 2. ΛCDM model with 3 massive neutrino species and thermalaxion: 68% and 95% CL allowedregions in the (∑mν, ma) planefor differentcombinations of data Only with Planck SZ cluster data a non zero value of axion mass isfavouredatthe 2.2σ No evidence for non-zero neutrino masses nor for non-zero axion mass. Giusarma et al arXiv:1403.4852 CMB+DR11+BAO+HST+SZ Cluster: CMB+DR11+WZ+HST+SZ Cluster: Evidence for neutrino mass of 0.2 eV at 3σ on only for one case

  11. MainResults(3) 3. ΛCDM model with 3 massive neutrino and ΔNeff=Neff-3.46masslessdarkradiationspecies: 68% and 95% CL allowedregions in the (∑mν, Neff) and in the (Neff, H0) plane The prior on the value of the Hubble constant from HST increasesthe mean value on Neff Giusarma et al arXiv:1403.4852 CMB+DR11+WZ+HST+BBN (Cooke et al.): NO EVIDENCE FOR Neff>3 CMB+DR11+WZ+HST+BBN (Iocco et al.): EVIDENCE FOR Neff>3

  12. MainResults(4) 4. ΛCDM model with 3 active massive neutrinos plus ΔNeffmassive steriles neutrino species: 68% and 95% CL allowedregions in the (∑mν, Neff) and in the (∑mν, mseff) plane The bound on Neff(∑mν) isslightlylarger (more stringent) than in masslesssterile neutrino scenarioduetothedegeneracywithmseff Giusarma et al arXiv:1403.4852 CMB+DR11+WZ+HST+BBN(Cooke et al.): NO SIGNIFICANT PREFERENCE FOR Neff>3 CMB+DR11+WZ+HST+BBN(Iocco et al.): SIGNIFICANT PREFERENCE FOR Neff>3

  13. BICEP2 measurements BICEP2:detectionatabout 5.9σfor B-mode polarization on large scales at 68% CL Ade et al ‘14 BICEP2 Collaboration Apparenttension with Planck+WPlimit: r<0.11 at 95% cl

  14. Whatistheimpact of BICEP2 measurementson neutrino properties? ΛCDM +r model with 1 massive neutrino (0.06 eV) and ΔNeff=Neff-3.046masslessdarkradiationspecies: ΛCDM +r model with 3 massive neutrino: Evidence for Neff>3 butno indication for neutrino masses r = 0.15±0.04 at 68% CL Giusarma et al arXiv:1403.4852 Extra relativistic component seems to solve the tensionbetween the Planck and BICEP2 experiments on r

  15. Conclusions • Constraints on the masses of the differentthermalrelics in differentscenariosusing the mostrecentcomological data • In the minimal three active massive neutrino scenario we found that CFHTLens survey displaces the bound on neutrino masses to higher value. Planck cluster data favours a non zero value on ∑mνof about 0.3 eVat 4σ. • In the scenario with thermalaxions and active massive neutrino specieswefoundthatonly considering the Planck SZ cluster data plus CMB+DR11+ BAO+HST there exists a prefernce for axion mass of 0.6 eVat the obout 2.2σ and only combining Planck SZ cluster data with CMB+DR11+ WZ+HST there is an evidence for neutrino mass of 0.2 eV at about 3σ. • In the scenario with massive neutrinos and ΔNeffdarkradiationspeciestheboundson∑mνarelessstringent. BBNconstraintsreducebothmeanvalueand the errors ok Neffsignificantly. • Considering B-modepolarizationmeasurementsby BICEP2 experiment +Planck+WP data, wefoundthatanextra realivisticcomponentcouldsolvethetensionbetweenthetwoexperimentsontheamplitude of tensor mode.

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