Dark matter in cosmology - Osaka University...Fine-tuned decelerated expansion DARK MATTER • We...

Dark matter in cosmology

Theory Center, KEK and SOKENDAI, Tsukuba

Kazunori Kohri 郡　和範

16/11/08 Kaz Kohri (KEK)

Introduc)on

16/11/08 Kaz Kohri (KEK)

Planck Satellite

Einstein’s Cosmological Constant

Or unknown scalar field?

Visible Matter

Invisible Matter

Not Even Matter

Friedmann equa)on

•  Hubble  parameter  

•  Density  parameter  

•  Cri)cal  energy  density  

•  Flat  universe  (K=0)

H(t ) = !a /a

H 2 = 8πG

3ρ - K

a2

Ω

j(t ) = ρ

j(t ) / ρ

cr(t )

ρcr(t ) = 3H(t)2 / (8πG)

ρ =ρΛ +ρ

CDM +ρ

b +ρ

R

ρm

=ρCDM

+ρb

−ΩK(t ) ≡ K / (aH)2 = Ω

Λ(t ) +Ω

m(t ) +Ω

R(t ) − 1 = 0

ΩΛ(t

0) +Ω

m(t

0) = 1

a(t): scale factor

Cosmic time (or the scale of the Universe)

Ener

gy d

ensi

ty

Cosmic temperature↓

13.7Gyr 105yr

Dark energy

(Cosmological constant, Quintessence)

Matter-radiation equality (EQ)

Higgs energy scale

テキスト

!10−56 !times!smaller!than!the!Higgs!pot.!energy!scale

!10−10 !sec

!1056 !times!larger!than!the!DE!scale

!1015 !K!(1015 !F)

30% ρm∝a −3

0.01% ρr∝a −4

70% ρΛ

~ const.

Ωm　　　　　　　ΩΛ

http://map.gsfc.nasa.gov/

Exponentially “accelerated”

expansion

(2nd Inflation?)

Contraction

Fine-tuned decelerated expansion

DARK MATTER •  We cannot observe them •  We do not know who they are

New supersymmetric particle (neutralino χ)

axion

Primordial black holes

16/11/08 Kaz Kohri (KEK)

Sterile neutrino

Properties of DM

•  Completely obscured optically

•  Gravitated toward the galaxy/clustes of galaxies

•  5 times more abundant than baryon (atoms)

•  Decelerating the cosmic expansion

16/11/08 Kaz Kohri (KEK)

Clear  Evidences?

16/11/08 Kaz Kohri (KEK)

Observing Doppler shift of 21 cm line of neutral hydrogen

1) Rotation curves of spiral galaxies

halo r

velocity

acceleration

Disk

a = v 2

r~ G M

r2

v ~ GM / r ?

Rotating  planets  in  solar  systemless  dark-‐‑‒matter  system  

16/11/08 Kaz Kohri (KEK)

v ~ GM / r

Rota)on  curve  

二間瀬敏史著　「なっとくする宇宙論」

Begeman, Broils,Sandars etal (91)

Dark Halo

gas

Stars (visible component)

velo

city

v ~constant

2)  Gravita)onal  Lensing  Effects  

二間瀬敏史著　「なっとくする宇宙論」

Gravita)onal  lensing  in  colliding  cluster  of  galaxies  

•  Red:  Baryon  observed  by  X-­‐ray  produced  by  brems  of  thermal  electron  

•  Blue:  DM  observed  by  gravita)onal  lens  

(2007)

σm

< ) ~ (2

Baryon σ/m ~ 4b/GeV is excluded

Bullet Cluster

Gravita)onal  Lens  Effect  •  Cosmos  Evolu)on  Survey  （コスモスプロジェクト）  •  2  square  degree,    500  thousand  galaxies,  0.05  arcsec  

1 Gpc Richard Massey et al (07) http://cosmos.phys.sci.ehime-u.ac.jp/~tani/Cosmos/PressRelease/

3)  Structure  forma)on  

•  Only  pure  fluctua)on  of  baryon  is  too  small  to  produce    LSS  because  of  oscilla)on  and  Silk  damping  

•  CDM  fluctua)on  evolves  aWer  maXer-­‐radia)on  equality  epoch,  which  is  ahead  of  baryon  fluctua)on  

•  Baryon  fluctua)on  catches  up  with  CDM  fluctua)on  aWer  recombina)on  

Cold Dark Matter (CDM) has an essential role for formation of Large Scale Structure (LSS), i.e, galaxies and clusters of galaxies

δ ∝ a(t )

16/11/08 Kaz Kohri (KEK)

Time-evolution of CDM fluctuation

Ma and Bertschinger (95)

-6 -5 -4 -3 -2 -1

Log a

Horizon reentry before matter-radiation equality epoch

∝a aEQ

CDM Baryon

photon

∝log(a)

CDM

Baryon

photon

∼ ∼

16/11/08 Kaz Kohri (KEK)

arec

Log a

Then a galaxy (made by baryons) is produced inside the CDM halo due to the gravity of dark matter

First, dark matter halo was produced in the early universe

Time-­‐evolu)on  of  the  DM  fluctua)on  to  produce  a  galaxy

ρDM

ρbaryon

~ 5

16/11/08 Kaz Kohri (KEK)

Baryon  Acous)c  Oscilla)on  (BAO)

16/11/08 Kaz Kohri (KEK)

Matter power spectrum in k-space

http://www.aip.de/groups/cosmology/

2-point corr. func. in real space

Bassett and Hlozek, arXiv:0910.5224 [astro-ph.CO]

CMB  observa)ons

16/11/08 Kaz Kohri (KEK)

Temperature  fluctua)on

16/11/08 Kaz Kohri (KEK)

Planck 2015 results. XIII, 1502.01589v3

Is  the  universe  open  or  flat?

16/11/08 Kaz Kohri (KEK)

https://map.gsfc.nasa.gov/mission/sgoals_parameters_geom.html

ΩK= 0

ΩK> 0

Flat  with  cosmological  constant  ΩK  ~  0  

16/11/08 Kaz Kohri (KEK)

http://background.uchicago.edu/~whu/animbut/anim3.html

ΩK= 1 − Ω

m− Ω

Λ~ 0

ΩΛ= 1 − Ω

m

Ω

CDM+Ω

baryon+Ω

Λ= 1 − Ω

K= 1

Wayne Hu’s HP

Open  universe  ΩK  >  0

16/11/08 Kaz Kohri (KEK)

http://background.uchicago.edu/~whu/animbut/anim3.html

ΩK= 1 − Ω

m− Ω

Λ~ 0.7

ΩΛ= 1 − Ω

m~ 0.7

Wayne Hu’s HP

Flat  with  cosmological  constant

16/11/08 Kaz Kohri (KEK)

http://background.uchicago.edu/~whu/animbut/anim3.html

ΩCDM~ 0.25, e.g., Ω

CDMh2 ~ 0.12 ΩCDM

+Ωb+Ω

Λ= 1

Ωm= Ω

CDM+Ω

b~ 0.3

Wayne Hu’s HP

Flat,  but  100%  dark  maXer

16/11/08 Kaz Kohri (KEK)

http://background.uchicago.edu/~whu/animbut/anim3.html

ΩCDM~ 1, e.g., Ω

CDMh2 ~ 0.5

ΩCDM+Ω

b+Ω

Λ= 1

Ωm= Ω

CDM+Ω

b

Wayne Hu’s HP

Combined  Figure  

Lahav-Liddle PDG (2009) Planck 2015 results. XIII, 1502.01589v3

galaxies (BAO etc)

+ Lensing potential reconstruction + Baryon Acoustic Oscillation (BA0)

Candidates  for  dark  maXer •  Weekly  Interac)ng  Massive  Par)cle  (WIMP)                                                                            

[Lightest  SUSY  Par)cle  (LSP)  neutralino  χ,  right-­‐handed  sneutrino　        ,  …]  

•  Axion  

•  Right-­‐handed  (sterile)  neutrino      

•  SuperWIMP  [gravi)no    ψμ,  axino                    ,  …]    •  Primordial  black  hole  (PBH)  •  …  

νR

νR(ν

s)

16/11/08 Kaz Kohri (KEK)

!a

a

Weakly-­‐interac)ng  massive  par)cle  (WIMP)

•  Value  of  the  annihila)on  cross  sec)on  is  close  to  the  Weak  one  

•  Relic  density  coincides  the  observed  value  (WIMP  miracle)  if  <σv>~3  ×10-­‐26  cm3/sec  

•  Supersymmetric  partners  can  be  the  dark  maXer  

neutralino ⇔ photon, Z-boson, Higgs

right-handed scalar neutino ⇔ Right-handed neutrino 16/11/08 Kaz Kohri (KEK)

Thermal freeze out of WIMP

σv = 3× 10−26cm3 / s

16/11/08 Kaz Kohri (KEK)

Boltzmann equation

nχ ∼

3Hσ v

frezeout

Ωχ ∼ 0.25σ v

0.1TeV( )2

⎛

⎝

⎜⎜⎜

⎞

⎠

⎟⎟⎟

−1 TFreezeout mχ / 23

Ωχ h2 does not depend on mχ Predicting TeV Physics!!!

∝Exp[-m/T]

ρDM

s= m

DM

nDM

s

x

F= m

TF

∼ 20 − 30

Indirect  detec)on  of  DM Annihilation or Decay?

Daughter particles Propagations of charged particles

16/11/08 Kaz Kohri (KEK)

Gamma-­‐ray  by  Fermi

Constraints from Dwarf steroidals by Fermi collaboration 16/11/08 Kaz Kohri (KEK)

Cosmological  bounds  on  annihila)ng  dark  maXer

Planck 2015 results. XIII. Cosmological parameters

For electromagnetic modes from CMB In order not to delay recombination

For b-bbar modes from BBN In order not to produce more D

Kawasaki, Kohri, Moroi (2015) 16/11/08 Kaz Kohri (KEK)

Galac)c-­‐center  gamma-­‐ray  excesses  and  dark  maXer  annihila)on

16/11/08 Kaz Kohri (KEK)

Daylan et al, 2014

Constraints  by  Fermi  gamma-­‐ray  saXelite

16/11/08 Kaz Kohri (KEK)

Fermi-LAT Collaboration (Ackermann, M. et al.) Phys.Rev.Lett. 115 (2015)

Primordial  Black  Hole  dark  maXer

16/11/08 Kaz Kohri (KEK)

Carr, Kohri, Sendouda, Yokoyama (2009)

Horizon mass with the density fluctuation of the order O(1) can collapse to a PBH

Mas

s fr

acti

on a

t th

e fo

rmat

ion

Frac

tion

to

dark

mat

ter

dens

ity

Carr, Kunel, Sandstad (2016)

PBH cannot become 100% DM?

Positron  and  an)proton    by  AMS-­‐02  or    future  CALET

Kohri et al, in preparation

But still large uncertainties in the propagation models 16/11/08 Kaz Kohri (KEK)

An)proton  excesses  and  annihila)ng  dark  maXer

16/11/08 Kaz Kohri (KEK)

Qui et al, arXiv:1610.03840 [astro-ph.HE] Cuocco et al, arXiv: 1610.03071v1

keV  sterile  neutrino  DM

16/11/08 Kaz Kohri (KEK)

Berlin and Hooper, 2016 Klasen, Michael et al. arXiv:1507.03800 [hep-ph]

Ω

νs~ 0.3 (m

νs/ keV)

Relic abundance decoupled before the QCD phase transition (Tdec >> 100 MeV)

Oscillation produces larger amount of DM

PeV  neutrinos  by  IceCube

IceCube collaboration M. G. Aartsen et al, 2015 IceCube collaboration

M. G. Aartsen et al, 2014 16/11/08 Kaz Kohri (KEK)

Lower  bounds  on  life)me  for  decaying  DM

Rott, Kohri, Park ,2015

To be consistent with the flux, but statistically insufficient to obtain an upper bound

16/11/08 Kaz Kohri (KEK)

Summary

•  (Cold)  dark  maXer  (CDM)  exists  in  the  Universe  with  the  energy  frac)on  of  27%,  or  5  )mes  larger  than  baryon  (atoms)  

•  There  are  many  candidates  of  CDM    such  as  WIMP,  axion,  PBH,  sterile  neutrino, …  

•  Our  next  step  is  to  detect  it  with  high  confidence  levels  and  reveal  its  nature  

16/11/08 Kaz Kohri (KEK)

To  answer  Sergey  Petcov‘s  ques)on

16/11/08 Kaz Kohri (KEK)

Future  constraints  on  neutrino  hierarchy    by  21cm,  CMB  and  BAO

•  Hierarchy  parameter Oyama, Kohri, Hazumi (2015)

rν≡

m3−m

1

Σmi

=> 0 normal hierarchy< 0 inverted hierarchy

⎧⎨⎪

⎩⎪

Future  constraints  on  neutrino  mass  by  21cm,  CMB,  and  BAO

Oyama, Kohri, Hazumi (2015)