Cosmological constraints on

sterile neutrino mass

in gravity

Hayato Motohashi

本橋 隼人 (RESCEU, The University of Tokyo)

1 2012.11.12-16 RESCEU symposium and JGRG22, Univ. of Tokyo

Alexei A. Starobinsky (Landau Inst.)

Jun’ichi Yokoyama (RESCEU)

in collaboration with

Two regimes of accelerated expansion

2

Reheating

gravity

can describe the accelerated expansion.

Primordial inflation

Late-time acceleration

3

Starobinsky, JETP Lett. 86, 157 (2007)

[arXiv:0706.2041]

Starobinsky, Phys.Lett. B91 (1980) 99

Appleby, Battye, Starobinsky, JCAP 1006, 005 (2010) [arXiv:0909.1737]

H.M., Nishizawa, PRD 86 (2012) 093514 [arXiv:1204.1472]

cf. model for both accelerated expansion

4

Local scale

Solar system test

Horizon scale

Expansion history

Testing modified gravity

Intermediate scale

Large scale structure

Time variation of EoS parameter

5

- 0.92 - 0.23

- 0.94 - 0.22

- 0.96 - 0.21

H.M., Starobinsky, Yokoyama

PTP 123 (2010) 887 [arXiv:1002.1141]

Komatsu et al.,

APJ Suppl. 192, 18 (2011)

[arXiv:1001.4538]

Growth index

Rapetti et al., arXiv: 1205.4679 6

H.M., Starobinsky, Yokoyama

PTP 123 (2010) 887 [arXiv:1002.1141]

Additional transfer function in gravity

gravity enhances matter power spectrum.

cancel

Massive neutrino suppresses matter power spectrum.

7

Constraint on from BBN

8

[331] Izotov, Thuan, Astrophys.J. 710, L67 (2010) [arXiv:1001.4440]

[332] Mangano,Serpico, Phys.Lett. B701, 296 (2011) [arXiv:1103.1261]

[333] Nollett, Holder [arXiv:1112.2683]

[122] Hamann et al, JCAP 1109, 034 (2011) [arXiv:1108.4136]

Abazajian et al [arXiv:1204.5379]

Constraints on and in ΛCDM

CMB

9

(95% CL)

(68% CL)

LSS

ΛCDM + Komatsu et al.,

APJ Suppl. 192, 18 (2011)

[arXiv:1001.4538]

Reid et al,

Mon.Not.Roy.Astron.Soc. 404

(2010) 60 [arXiv:0907.1659]

Constraints on and in ΛCDM

10

Riemer-Sorensen et al

[arXiv:1210.2131]

ΛCDM cosmology

sub-eV

sterile neutrino

Sterile neutrino mass 1 eV

ΛCDM model

11

Mention et al.,

PRD 83, 073006 (2011)

[arXiv:1101.2755]

Giunti, Laveder,

Phys.Rev. C83 (2011) 065504

[arXiv:1006.3244]

Antonello et al,

[arXiv:1209.0122]

Neutrino oscillation

MCMC analysis: ΛCDM vs gravity

12

H.M., Starobinsky and Yokoyama, arXiv:1203.6828

3 massless and 1 massive neutrino with mass = 1 eV

WMAP7, SDSS DR 7

Better fit : 10.7 (Δ AIC = 8.7)

GR : , :

ΛCDM

MCMC analysis: ΛCDM vs gravity

13

H.M., Starobinsky and Yokoyama, arXiv:1203.6828

3 massless and 1 massive neutrino with mass = 1 eV

WMAP7, SDSS DR 7

Better fit : 10.7 (Δ AIC = 8.7)

GR : , :

ΛCDM

WMAP

ΛCDM

SDSS

14

Summary

14

Cosmology based on ΛCDM model

Sterile neutrino mass 1 eV

Neutrino oscillation experiments

Sterile neutrino mass 1 eV

gravity can resolve the tension.