Constraints on the neutrino mass by future precise CMB polarization and 21cm line observations Yoshihiko Oyama The Graduate University for Advanced Studies KEK cosmophysics group Collaborators Masashi Hazumi (KEK CMB group) Kazunori Kohri (KEK cosmophysics group)

2 SKA Phase1, Phase2 POLARBEAR-2 or Simons Array ＋ Planck ＋ temperature, E-mode, B-mode E-mode, B-mode 21cm line brightness temperature （ z=7-10 ） ◇ Focused experiments

3 SKA Phase1, Phase2 POLARBEAR-2 or Simons Array ＋ Planck ＋ temperature, E-mode, B-mode E-mode, B-mode 21cm line brightness temperature （ z=7-10 ） ◇ Focused experiments ＋ Baryon Acoustic Oscillation (BAO)

2. Effects of neutrinos on the growth of the density fluctuations growth of the density fluctuations 4 contents 1. 21cm line observations 3. Future constraints on the neutrino mass by CMB and 21 cm line 4. Summary

2. Effects of neutrinos on the growth of the density fluctuations growth of the density fluctuations 5 contents 1. 21cm line observations 3. Future constraints on the neutrino mass by CMB and 21 cm line 4. Summary

6 ・Introduction ・21cm line brightness temperature and the power spectrum 1. 21cm line observations

7 21cm line results from hyperfine splitting of neutral hydrogen. Spin =0 singlet Spin =1 triplet proton 1S state ◇ 21cm line

S.G. Djorgovski et al. & Digital Media Center, Caltech. ◇ Cosmological 21 cm radiation 8 The epoch of reionization Dark age CMB Cosmic dawn (The late stage of the dark age)

This signal has information of the matter distribution. ◇ 21cm line and cosmology 9 (2006) Astrophys.J.653: ,2006 M.McQuinn, O.Zahn, M.Zaldarriaga, L.Hernquist, S.R. Furlanetto

◇ Advantages of 21 cm line observations 21 cm line observations 10 １. Non-linear effects are small Z=0 Z=3 linear non linear linear non linear ２. Broad redshift range ・ A lot of independent Fourier modes. ・ The time evolution of the density fluctuations

11 ・Introduction ・21cm line brightness temperature and the power spectrum 1. 21cm line observations

12 1. Peculiar velocity of gas 2. Expansion of universe Fluctuation of baryon

2. Effects of neutrinos on the growth of the density fluctuations growth of the density fluctuations 13 contents 1. 21cm line observations 3. Future constraints on the neutrino mass by CMB and 21 cm line 4. Summary

This effect erases their own fluctuation s within such scales. This effect erases their own fluctuation s within such scales. ◇ Effects of neutrinos on the growth of the density fluctuations the density fluctuations 14 neutrinos run up to the horizon scale (Free-streaming) ~ Horizon scale

Matter power spectrum 15 Heavier neutrino mass This suppression becomes larger. The free-streaming effects of neutrinos

16 Polarization of CMB Power spectra of CMB polarization (lensing B-mode ) The free-streaming effects of neutrinos By observation of CMB polarization, we can constrain the neutrino mass.

17 WMAP 9-year + ACT + SPT + BAO + H 0 ◇ Current neutrino mass constraints Planck (temperature) Planck (temperature) + WMAP polarizations ＋ ACT + SPT + BAO

2. Effects of neutrinos on the growth of the density fluctuations growth of the density fluctuations 18 contents 1. 21cm line observations 3. Future constraints on the neutrino mass by CMB and 21 cm line 4. Summary

19 ◆ CMB, 21cm, BAO観測実験

20 We took account of combinations of above 2 experiments and Planck satellite. KEK CMB group is developing these experiments. ◆ POLARBEAR-2 ◆ Simons Array POLARBEAR-2 × 3 95, 150, 220 GHz 95, 150 GHz ◇ CMB polarization experiments

◇ 21cm line experiment ◆ SKA (Square kilometer Array) SKA low frequency (Australia) Construction of Phase1 will start in We took account of Phase1 and Phase2 (Phase2 has 10 times larger collecting area.)

22 ◆ Dark Energy Spectroscopic Instrument (DESI) Instrument (DESI) ・Galaxy survey (2018年から観測開始) ◇ BAO Observation

23

90% C.L CMB + DESI (BAO)+ 21cm line By Planck + Simons Array + SKA, the neutrino total mass is detectable at 95%C.L. CMB+DESI +SKA Simons Array + DESI

25 ◆ With residual foregrounds Motivation: How much is it necessary to remove foregrounds?

90% C.L Because constraints from CMB become weaker, combinations of CMB and SKA is more important. CMB + DESI (BAO)+ 21cm line CMB+DESI +SKA Simons Array + DESI

27 ◆ Constraints on the neutrino mass hierarchy mass hierarchy

◇ The neutrino mass hierarchy 28

◇ Effects of the mass hierarchy 29 Ratios of matter power spectra (at z = 8) The differences due to the mass hierarchy larger

30 ◆ Parameterization of the mass hierarchy T. Jimenez, T. Kitching, C. Pena-Garay, L. Verde, JCAP 1005:035,2010 Dotted lines express allowed regions by oscillation experiments

31 In the inverted case, SKA phase1 + Simons Array + Planck has enough sensitivity to determine the mass hierarchy. Normal hierarchy Inverted hierarchy CMB+DESI +SKA1 SKA2 CMB+DESI +SKA1 SKA2

32 In the inverted case, SKA phase1 + Simons Array + Planck has enough sensitivity to determine the mass hierarchy. Normal hierarchy Inverted hierarchy CMB+DESI +SKA1 SKA2 CMB+DESI +SKA1 SKA2

33 In the inverted case, SKA phase2 + Simons Array + Planck has enough sensitivity to determine the mass hierarchy. Inverted hierarchy CMB+DESI +SKA1 SKA2 Normal hierarchy CMB+DESI +SKA1 SKA2

34 In the normal case, SKA phase2 + Simons Array + Planck has enough sensitivity to determine the mass hierarchy. Inverted hierarchy CMB+DESI +SKA1 SKA2 Normal hierarchy CMB+DESI +SKA1 SKA2

2. Effects of neutrinos on the growth of the density fluctuations growth of the density fluctuations 35 contents 1. 21cm line observations 3. Future constraints on the neutrino mass by CMB and 21 cm line 4. Summary

We studied sensitivities of ■ We studied sensitivities of 21cm line (SKA) + CMB polarization observations (POLARBEAR-2, Simons Array) to the neutrino total mass Summary ■ Planck + Simons Array + SKA may determine the neutrino mass hierarchy.

37