Dark matter in cosmology - Osaka University...Fine-tuned decelerated expansion DARK MATTER • We cannot observe them • We do not know who they are New supersymmetric particle (neutralino

Dark matter in cosmology

Theory Center, KEK and SOKENDAI, Tsukuba

Kazunori Kohri 郡　和範

16/11/08 Kaz Kohri (KEK)

Introduc)on


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


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


Clear Evidences?


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


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 )


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

∼ ∼


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


Baryon Acous)c Oscilla)on (BAO)


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


Temperature fluctua)on


Planck 2015 results. XIII, 1502.01589v3

Is the universe open or flat?


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

ΩK= 0

ΩK> 0

Flat with cosmological constant ΩK ~ 0


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



ΩK= 1 − Ω

m− Ω

Λ~ 0.7

ΩΛ= 1 − Ω

m~ 0.7

Wayne Hu’s HP

Flat with cosmological constant



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



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)


!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


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


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


Daylan et al, 2014

Constraints by Fermi gamma-‐ray saXelite


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

Primordial Black Hole dark maXer


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


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

keV sterile neutrino DM


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


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


To answer Sergey Petcov‘s ques)on


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)

Documents

Dark matter in cosmology - Osaka University...Fine-tuned decelerated expansion DARK MATTER • We cannot observe them • We do not know who they are New supersymmetric particle (neutralino