2020年代の宇宙論・構造形成(中間報告)
高田昌広（班長）
大栗真宗（サブリーダー）
班員：浜名崇(NAOJ), 樽家篤史(京大), 齊藤俊(IPMU), 宮武広直(Princeton/IPMU), 奥村哲平(IPMU), 鈴木尚孝(IPMU), 日影千秋(名大), 高橋龍一(弘前大), 西澤淳(名大),
どなたでも参加してください。（特に若い方）大歓迎です！

Big Questions	• 宇宙の始まりは？(インフレーション）‒ 原始密度ゆらぎの物理• 宇宙の加速度膨張の起源は？
‒ ダークエネルギー or 重力の修正• 我々はどこから来たのか？
‒ 構造形成・銀河形成の物理の理解‒ ダークマターの正体は？ニュートリノ
宇宙論の強み：素粒子・宇宙物理・天文の融合領域

議論のポイント• サイエンスの重要性のインパクト• サイエンス 手段・手法• 独自性：可視光・赤外の観測でしかできない計画か？
• サイエンスの発展性、他の分野との相乗効果は？
• 実現可能性は？
• 世界の情勢、世界との競争力

1.2EEl(l+1)Cl /2π [µK2]

BICEP2 (March 17 2014)	

EE

10.8

B2xB2
B2xB1100

0.6

B2xB1150

0.40.2

B2xB2
B2xB1cB2xKeck (preliminary)

0BBl(l+1)CBB/2π [µK2]

0.05

0.03

0.03
0.02
0.01
0−0.01050

100
Multipole

150200

0.02

CMB

10.01

0.8

050

100

150200Multipole250300• Evidence of quantization of space-time(quantum gravity)? 	

• Used 100×150GHz cross to “reject”
representative spectra of synchrotron
and dust only at ~2 sigma	

0.40.20−4Dust−0.01+1.25

β = −1.55−0.86

0.6

Sync

0Likelihood

BB2l(l+1)Cl /2π [µK ]l0.040.04−202
Spectral index (β)

4should wait until Oct (PlanckPol)…	

Talk by Douglas Scott@BICEP2, Perimeter Institute (April 4)	

	!
Physics of Inflation (B-mode)	
tcpamI
hHig• Inflation-induced gravitational wave 	

CMB B-mode determines the energy scale of inflation	
LiteBIRD	

• BICEP2 implies a large field inflation (Lyth 97)	

Landscape picture of inflation	l Hl + 1L Cl
2p2500Frevogel, Kleban+14	

2000Murayama+ 14	15001000

This model	

500

Bousso+14	

10-1

tunneling	

001020Open inflation (Yamamoto+96, Linde, Sasaki+)	
10-810-120
0103040l50

Sasaki-san’s slide	宇宙の曲率• 宇宙の大域的な構造• 一般相対性理論の予言• fundamental quantity	

• Inflationary scenario viable inan open Universe If aclose curvature is found,most of inflation models areruled out (Nomura & Guth12; Kleban & Shillo)	

close	open	flat	Baryon Acoustic Oscillation(BAO)	The typical scale of CMB
Newly establishedgeometrical probesince 2005, based on
the CMB physics(therefore very robustmethod)	

anisotropies is determined by
the sound wave of photonbaryon fluid at z~1100 (to a0.07% accuracy by Planck)	

BAO (cont’d)	

• Measure galaxy clusteringstrengths: 2pt correlations(or P(k))	

dVr

dV rBAO~150Mpc

θ
dP = n g2 [1+ ξ g (r)] dV 2DA(z)• Find a tiny excess in thegalaxy pairs at BAO scale(a priori known from CMB
to be ~150Mpc)	

rBAO = DA (z)θ obs
Eisenstein et al 05	

Baryon Oscillation Spectroscopic Survey 
(BOSS: 1999- )	
• The BAO-dedicated spectroscopic
survey, a part of the 3rd generationof SDSS (SDSS-III), using thededicated 2.5m telescope in NM,USA	• U. Tokyo is the participation
institute (anyone at U. Tokyo hasaccess to the data) 	

• The new BAO result using theData Release 11 (DR11) justannounced (Dec 18, 2013)	

BOSS DR11 BAO (Anderson+13) 	
Shun Saito (IPMU)	

> 7σ detection	

A 2σ-level tension between BAO and CMB
constraints; we should wait for the 2nd-yaer
Planck result, coming around Sep 2014)	

Model-independent
reconstruction of curvature	Comoving radial distance 	

Comoving angular distance 	

BAO	BAO	• By combining measurements of H(z) and DA(z) via BAO,
we can constrain the curvature in a model-independentway (only assumed metric theory and light propagation) 	

forecasts	

PFS (Subaru 100 nights)	

DESI (4m 500 nights)	

15

Curvature parameter (cont’d)	(Preliminary)	

Observable universe with galaxies	
• SDSS-I – IV (redgalaxies, emissionline galaxies), z<0.7	

• PFS (OII-emitters):
0.8<z<2.4	

• Other emission
lines, OII, Lymanalpha (potentially upto z~6?)	

• QSO & Lyman-alphaforests (z<4-5)	

• Eventually 21cm 	
Tegmark & Zaldarriaga 09	

DE reconstruction	ρde (z ⊂ zi )Ωde (z) =3H 2 (z)8π G

Cosmic structure formation	

gravity (dark matter)time	cosmic expansion (dark energy)• The present-day large-scale structure arises froma gravitational amplification of the tiny
perturbations in the early universe	• Assume Cold Dark Matter (CDM) for unknown
source of gravity – cold, massive & collision-less	• LCDM = current standard model	

• Gravity (DM) vs. Cosmic expansion (DE)	

Planck collaboration	
19宇宙の加速膨張問題：
ダークエネルギー or 重力の破綻？
• 観測事実は宇宙の加速膨張

1Rµν − gµν R + Λgµν = 8π GTµν
2#&1
Λor Rµν − gµν R = 8π G %Tµν −gµν ('$28π G• ΛCDMモデル：アインシュタイン重力(GR)に基づく、宇宙膨張、構造形成のモデル（>6パラメータ: Ωm, Ωb, ns, …, +Λ）• GRは ~1mm ‒ 10Gpc (29桁)にわたり正しいのか？
• ２つのシナリオの区別は？：膨張則の測定（BAO, SN）と構造形成史の測定（WL, galaxy clustering, 銀河団）が組み合わせることが必要

Dark Energy vs. Modified Gravity	
A most general from of metric in matter-dominated era	

• LCDM: 	

• Gravitational lensing:	

• Peculiar velocities of galaxies (redshiftspace distortion): 	

• Lensing + RSD allows a model-independent
test of gravity at cosmological scales	RSD measurement	
105

CMASS-DR11 northCMASS-DR11 south
best fit northMonopole

104• The state-of-art
measurement by BOSS
Quadrupole(z~0.5)	

103• So far the measurement isBeutler, Saito+14	
consistent with Einstein
4 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16r 0.18
= 79.8 0.2
2gravity	k [h/Mpc]0-2• Biggest uncertainty: galaxy-44r = 68.7
bias	
222

6P2/ mP 6P0/ mP0PL(k) [Mpc/h]3

best fit south

0-2-4

0.05

0.1
k [h/Mpc]

0.15

0.05

0.1
k [h/Mpc]

0.15

2

0.2

0.2

100

100log M⇤ /hlog M⇤ /h2M

=11.49(68%)

2M=11.83(95%)

Combined probes: Lensing (imaging) + Clustering (spec-z)	
[11.10,12.00][11.10,12.00]

50300⌃(hM /pc2 )wp rp (h 2 Mpc2 )350

S. More	• Lensing: directly measure the DM distribution, but projected	200• Clustering:
3D mapping of galaxy distribution; a much higher S/N, but galaxy
150 uncertainty	

bias
100100• More,Miyatake, Mandelbaum, MT, Spergel, et al. (2014): CFHTLenS (3.6m[11.30,12.00]
imaging,only ~120 sq. deg) + BOSS (2.5m spec-z, 10000 sq. deg) 	
50
250

101log M⇤ /hlog M⇤ /h2M=11.87(68%)

2M=12.20(95%)[11.30,12.00]

clustering 	oflensing (cross-correlation	300⌃(hM /pc2 )wp rp (h 2 Mpc2 )

350

250
200
150

spec-z gal positions
with backgroundgalaxy shapes) 	

101

100

100log M⇤ /hlog M⇤ /h[11.40,12.00][11.10,12.00]50)

350
300

100

2M=11.91(68%)=11.49(68%)

2M=12.23(95%)=11.83(95%)[11.40,12.00][11.10,12.00]

101rp (h 1 Mpc)

102

10

1100rp (h 1 Mpc)

101

More, Miyatake et al. (2014)	
growth rate	HSC (1400 sq. degrees) promises more than afactor 3 improvement!	

A journey through the “observed” galaxy distribution (1.5M gals)	
Sloan Digital Sky Survey (1999-) with the dedicated 2.5m telescope 	

可視光の強み！

A journey through simulated universe (Millennium Simulation)	

Nature of Dark Matter
Gravitational lensing	

8π GGµν = 4 Tµνc
⇒ light path: x = x[z; gµν ]The curved space-time bends “light path”		

The lensing distorts images of distantgalaxies	
Cosmic acceleration (DE)	

Lensing strength =(geometry of the universe)× (total matter of lens(es)) 	 Dark matter	

distorted galaxy shapes	DM distribution of galaxy clusters	
• Collected Subaru data of 50 clusters, all the most X-ray luminous
clusters accessible from Subaru (about 15 Subaru nights; 5 yrs)	

• The averaged DM distribution from the combined WL data	Ncluster=1	

Ncluster=20	

Ncluster=5	

Ncluster=50	

Nobuhiro Okabe#

Signal-to-Noise ratio(S/N)~5 for onecluster ⇒ S/N~30
when 50 clusters
combined	
Okabe et al. 13, ApJ Letters#
Okabe, MT+ 10,PASJ	DM distribution of galaxy clusters (cont’d)	
The average massdensity profile of 50
clusters	

N-body simulation of CDM
structure formation	

• Subaru WL result shows aperfect agreement with theCDM model prediction	

• ~5% accuracy of the cluster
mass determination	

Shape of dark matter halo	Oguri+12: a detection of dark
matter halo shape with WL+strong
lensing for Subaru cluster data (alsosee Oguri+10)	

• Collision-less nature of DM
predicts that a shape of haloshould be aspherical	

• CDM predictions seemconsistent with WL
measurements on clusters	• What about small scales?
(galactic scales and smallerscales)	

– More sensitive to the nature ofdark matter: warm (~keV) vs. cold	

– Baryonic physics is also significant	– Strong lensing? 	

z=3, DM (blue) + GAS (red)'!

Neutrino Mass	w Mν (1.2eV)	

w/o Mν	%!
y [ h-1 Mpc ]• We know neutrinos are massive(Kamiokande; SuperK)	

• The absolute mass scale unknown	

• Partly contribute to dark matter	• Suppress the growth of large-scale
structure at small scales	&!

z=3, DM (blue) + GAS (red) + ! (green)

$!

#!

"!

!

Dark matter	Gas particles	
2040

Gas particles	

6080

100

6080

100"("GAS2040"("DMNeutrinos	
0.90

0.95

1.00
"("!

1.05

1.10Large-scale structure 
for a CDM+ν model (cont’d)	

Research Highlight	

Saito, MT & Taruya 08 PRL; 09, 11 PRD; also Ichiki, MT & Takahashi 09 PRD; Ichiki & MT 12 PRD	This work: WMAP5+LRG
1with PT model (k=0.1h/Mpc)

L/Lmaxmax

WMAP5+LRG
with R09 (k =0.1h/Mpc)
max

0.5

WMAP5 only
000.5

11.5

Y m [eV]
i0

4−0.5

2bw

2−10−1.5−2−2−2.5
00.5

11.5

−40Y mi [eV]••••Applied the model to SDSS LRG power spectrum measurement	Included effects of nonlinear clustering, nonlinear bias, and dark energy	

Obtained a robust constraint on neutrino mass:	Fukugita & Yanagida (86)	
Goal for SuMIRe: 	

0.5

1Y mi [eV]PBH	• Kepler: satellite mission for exoplanet
search (~3000 planets reported)	

• Griest et al. proposed to use theKepler data to search for microlensing
events by PBHs	

• No strong candidate	

Kepler (NASA: 09-13) 	

New constraints on PBH	Now no window in the PBH mass range	EROS+MACHO
E

10−2

Femtolensing
Capture by NSs in GCs,
this work
Star FormationΩ PBH / Ω DM

100

10−4

KEPLERFIRASHawking

WMAP3

10−610−8 15101020

1025

1030

BH mass, g1035

1040

Capela et al. 13	Cross-correlation of galaxies and IGM gas	
• A series of amazing works by Brice Menard (JHU/IPMU)	
(one tracers have spec-z)	

dN/dz	

Composite QSO spectrum	
Zhu & Menard 12	銀河形成の激動期(z~2-3)：
暗黒物質、星形成、ガス• 「統計的」重力レンズ → 銀河まわりの暗黒物質分布 (z<1.5)• 背景光源（QSOと究極的には銀河）と前景銀河の相相関 → 銀河ハロー
内のcold ダスト (z<3.5)

Dekel et al. 2009, Nature	• 背景光源スペクトルと前景銀河の相相関（例、HSC-SDSS/BOSS) →銀河ハロー内の矮小銀河 (z<1)• 赤外線: warm ダスト (z~3)• 重力レンズで増光された遠方銀河の２次元面分光（例、HSC-TMT） →銀河の回転曲線の進化 (z<5)

階層的構造形成シナリオにおける銀河形成「物理」の系統的な理解

z~2 galaxy in hydrodynamicalsimulation 	宇宙論的銀河形成研究：
多角的視点、多波長、理論＋観測…
SDSS	Subaru	

分離角1分以内の	分光銀河ペアの個数	
• HSC ‒ SDSS/BOSS
QSOs/Galaxies• HSC/SDSS ‒ Subaru
AO• HSC ‒ PFS• HSC/PFS ‒ TMT• HSC/PFS ‒ ALMA
• 宇宙論シュミレーション

The world
situation	

KIDS (2012-)	

BOSS (2009-)	
Subaru SuMIRe (2013- ) 	

Euclid (2020)	

BigBOSS (2015?-)	

DES (2012-)	

LSST (2020?-)	

WFIRST (2020?-)	

NSF funding ($27.5M) in FY2014 for LSST construction now started	

LSST survey (2022-2032 if everything goes well)	

その他のトピック• 原始密度ゆらぎの復元（構造形成の非線形性の物理的理解）• ダークマターハローと銀河の関係• 超新星サーベイ• QSO吸収線宇宙論• 物理定数の時間進化• TMTによる宇宙膨張の直接測定(超高分解能分光)• 全天偏光サーベイ（CMB前景放射の補正）

宇宙論に必要な銀河サーベイの方向性• Imaging and spec. survey for the same region of the sky	– Wider area (wider FoV + high multiplexity)	

– Up to higher redshift without any gap in redshift (widerwavelength coverage; ground vs. space)	

– Denser sampling of galaxies in imaging and redshift	– HSC + PFS very powerful	• Cosmology = Statistics	

– Various cross-correlation: imaging – spec-z galaxies, CMB 2nd effects,
cold gas in IGM, warm gas in galaxies (via infrared such as SPICA)	

– Time-domain survey: microlensing, supernovae	

– A follow-up detailed observation of interesting objects with TMT 	

• 銀河形成・バリオン物理の理解の重要性‒ 銀河、AGN班との連携‒ シミュレーション？