Ki Young Choi

Early Universe and
Dark Matter
Ki Young Choi
Ki Young Choi
Sobaeksan on 11th November, 2014
1
Tuesday, November 11, 14
Contents
• The early Universe
• Inflation, reheating
• Baryogenesis
• What is Dark Matter?
• Candidates of Dark Matter
• Formation, evolution and identification of Dark Matter
• Astrophysical phenomena
• Cosmic ray, radio, X-ray, gamma-ray, neutrino, etc
2
Tuesday, November 11, 14
Satu
rday
, Ju
ne 8
, 13
Interactions
, Ju
ne 8
, 13
Sa
tu
rd
ay
,J
un
e
8,
13
Satu
rday
e 8, 13
Expanding Universe
3
Tuesday, November 11, 14
Fundamental particles
Standard Model
Higgs
4
Tuesday, November 11, 14
Standard Model
+
Dark Matter
+
Inflaton
+
................
5
Tuesday, November 11, 14
+
modified
gravity
• Inflation
The problems in the standard cosmology
- the horizon problem
- the flatness problem
- the structure formation problem
Inflationary models: old, new, Starobinsky, chaotic, hybrid, natural, Higgs
brane-inflation, .....
- Power spectrum, spectral index, running, ...
- Tensor spectrum, tensor-to-scalar ratio, spectral index,...
- Non-gaussianity: bi-spectrum, tri-spectrum, ...
- isocurvature perturbation,
Problems: no known realistic model, flat potential, eta-problem, transPlanckian problem, ...
6
Tuesday, November 11, 14
• Inflation
Inflation explains why our Universe is so flat and homogeneous and also
how the small cosmological fluctuations formed in the early Universe.
During reheating process, all the particles in the plasma are produced and
make the Universe hot and dense.
After reheating, the standard big bang cosmology begins with these initial
conditions: Primordial power spectrum of the relativistic plasma.
7
Tuesday, November 11, 14
• Baryogenesis
In the period of thermal equilibrium with B-violating operators, the
asymmetry between baryons and anti-baryons disappear.
In our Universe, only baryons dominate with negligible antibayons.
For this, we believe that there was some mechanism to make the
asymmetry: baryogenesis with Sakharov condition.
Heavy particle decay, leptogenesis, electroweak baryogenesis,
Sphaleron, .....
8
Tuesday, November 11, 14
atom, molecule
• Evolution of states in the Universe
Very Cold
neucleus
Structure formation
electron
Recombination,
photon decoupling
: CMB
Galaxy
Gas
Matter-dom.
Very Hot
Radiation-dom.
photons, Quarks,
gluons, electrons..
protons, neutrons,
electrons, photons
thermal equilibrium
BBN
Quark-hadron transition
9
Tuesday, November 11, 14
photons,
electrons,
light nuclei
directions in the Universe. The neutral atoms
curve ofcorresponding
spiral galaxy
• Rotation
equality
to 10 such
to 12assec
or the1
finally
forms
the structures
galaxy,
cluse
The radiation and relativistic particles in
decreases as T to the 4, however non-relativistic
at some point matter dominates the Universe
v ⇠ const.
equality corresponding to 10 to 12 sec or the1
• Dark Matter: why do we need them?
z+1=
R(t0 )
R(t)
- Galactic rotational curve
v = const.
- Cluster scale
• Bullet cluster
- CMB
1Mpc
1
v/p
R
f
M=
Z
r
0
GM m
mv
⇢ /2 const.
= [Clowe et.al,
v/
Two colliding clusters of galaxies
r2
r
30
Tuesday, August 20, 13
⇠ 220 km/
sec
(1E 0657-558)
The bulletvcluster
Optical X-ray Gas Dark Matter
- LSS
2
⇢(r0 )r0 dr
v ⇠
⇢ / T3
f (~v ) = fgal (~v + ~v +
- Gravitational lensing
⇤CDM
⇢ / T4
⇢
⇢
= 2.57 ⇥ 10
log10
h vith
Planck Collaboration: The Planck mission
Gravitational potential is located in a Dark Matter (blue)
other than the ordinary matter (red)
1
36
Tuesday, August 20, 13
Fig. 14. The SMICA CMB map (with 3 % of the sky replaced by a constrained Gaussian realization).
10
Tuesday, November 11, 14
G
1
1.29 ⇥ 10 7 GeV
'
100 GeV
Gravitational lensing
Fig. 15. Spatial distribution of the noise RMS on a color scale of 25 µK
for the SMICA CMB map. It has been estimated from the noise map
9
1. Dark matter and baryons energy
begins to dominate the Universe from
the cosmic
log ρ age around
log t
1012 sec .
dp (t) = 2t
Tuesday, November 11, 14
dp (t) = 3t
(1)
(2)
(Ω0 = 1)
(3)
l(l + 1)Cl /2π (µK 2 )
(4)
m(z) ≡ −2.5 log10 F = 5 log10 (1 + z) + 5 log10 r1 (z) + const.
(5)
F=
L
2
2
11
2
dL = R0 r1 (1 + z)
(6)
as
T
to
the
4,
however
non-relativistic
matter
as
T
to
the
tter. Short introduction on the needs of dark matter in
directions
in the
Universe.
The of
neutral
atoms
collapse
due
to
t the present
universe.
What
is the candidates
dark
point
matter
dominates
the
Universe,
it
is
called
Radia
Dark
Matter
dominated
Universe
•
signaturesforms
of them with
recent
anomalous such
observations.
finally
the
structures
asthe1
galaxy,
clusters
of galaxies
orresponding
to
10
to
12
sec
or
eV
of
temperature.
mental particles at low energy in the standard model,
Matter-dominated
Theall
andUniverse,
relativistic
particles
in(1)
thermalVacuumequilib
log
ρ radiation
s. They
existed Radiation-dominated
in the early
at that time
dominated
: relativistic
particles
:
non-relativistic
ot.
All
the
particles
were
in
the
plasma
and
interacts
decreases as T to the 4, however non-relativistic matter as T to
in the thermal equilibrium with a given temperature.
Baryons
+ DM it is called R
at
some
point
matter
dominates
the
Universe,
4
3
e is expanding and the density and temperature of the
p
e phase transition
happens. At 100
the 12
quarkequality
corresponding
to MeV
10 to
sec or the1 eV of temperat
and 1 MeV neutrinos decouples and electron-positron
and neutron
combine to make light nuclei. At 1 MeV,
4
0
r the photons decouple
tron to make neutral atom and
ecoupled photon is the
from all4
3
3
2 CMB we observe now
⇢
/
R
⇢
/
R
m
e. The
neutral
atoms
collapse
due
to
gravitation
and
l
res such as galaxy, clusters of galaxies etc.
4
lativistic particles in thermal equilibrium the density
⇢
⇠
E(t)
n(t)
/
R(t)
r
however
10 non-relativistic matter10as T1 to the 3. There27
3
3
r dominates the Universe, it is called Radiation-Matter
⇢
⇠
M
n(t)
/
R(t)
m
o 10 to 12 sec or the1 eV of temperature.
(z = 0)
2t
d (t) = 3t ⇢ / R
(Ω = 1)
1)C /2π (µK )
⇢/R
⇢ ⇠ E(t) n(t) / R(t)
⇢
⇠ M n(t) / R(t)
(2)
(3)
(4)
og (1 + z) + 5 log r (z) + const.
(5)
⇢ / hconst.
vi ' 10
cm /s
log ρ
log t
12
(z ≃ 0.4) (1)
log
ρ
log
t
10
sec
Redshift
1
(z
≃
5000)
2
(z = 0)
27
3
(1)
T
∼
1
eV
T
∼
1
MeV
dL = z + (1d
−R(t
q0 )z
+
·
·
·
z
≃
3200
eq
)
0
=
R
r
(1
+
z)
d
(t)
=
2t
d
(t)
h
vi
'
10
cm
/s
(6)
p
p
L
0
1
2
present
z
+
1
=
(1)
dp (t) = 2t
dp (t) = 3t
(2)
(z ≃ 0.4)
+ z)2
R(t)
Matter-Radiation
Equality
!
%
17
T
#
$
!
"
−1−3ω
−1
log
ρ
log
t
10
sec
5
(r
,
0,
0)
(r
,
0,
θ)
0
"
12
1
1
R
(z
≃
5000)
R
ρ
0.26
⇠
10
2
2 2
M
(Ω
=
1)
(3)
0
ṘTuesday,
Ωi0
−3
(Ω0 − 1)
=H
(2) 0 = (Ω0−5=
1) = 1
≃ 5000
=
November
0 R011, 14
2. Dark matter density and its
perturbation affected the CMB
temperature anisotropies.
13
Tuesday, November 11, 14
equality corresponding to 10 to 12 sec or the1 eV of temperature.
• Dark Matter in the CMB temperature perturbation
( ⇤CDM + power law spectrum)
The positions of the peaks depends⇢m,0
on the expansion
3
⇠
2
⇥
10
history after last scattering
⇢ ,0 Energy density of Matter, DE
2.7
34
3
nv
⇠
E
T
=
2.7
K
⇢
=
4.8
⇥
10
gram
cm
The gravitational potential is dominated
by DM ,0at the last scattering moment
0
since it⇢ism,0
the⇠matter-dominated
10 30 gram cm 3epoch. The amplitude is strongly depends on
the density perturbation of Dark Matter.
✓
◆
⇢ of
Density
perturbation
baryon
es in the Cosmic Microwave
Background
21 DM, radiation,
3 1 GeV
v ⇠ 100 km/ sec
n=
⇠ 0.3 cm
⇠ 10 40 cm 2
m
m
⇢DM (Sun) ⇠ 0.3 ± 0.2 GeV/ cm3 ⇠ 5 ⇥ 10
⇢air ⇠ 10
3
gram/ cm3
gram/ cm3
↵2
h ann vi ⇠
⇠ 10
2
(300 GeV)
14
Tuesday, November 11, 14
25
9
GeV
2
3. Dark matter density perturbation
seeded the structure formation of the
large scale structures such as galaxies,
clusters of galaxies, etc from the age of
Universe at 10^6 secs.
15
Tuesday, November 11, 14
Universe is expanding and the density and temperature of the
es. So the phase transition happens. At 100 MeV the quark3
25
Dark
Matter
for
the
Large
scale
structure
formation
•
(Sun)
⇠ 0.3 ±decouples
0.2 GeV/and
cm electron-positron
⇠ 5 ⇥ 10
gram/
on occurs, and ⇢1DM
MeV
neutrinos
3
3
e proton and neutron
combine
to
make
light nuclei. At 1 MeV,
⇢air ⇠ 10 gram/ cm
with electron to make neutral atom and the photons decouple
2 observe now from all
a. The decoupled photon is the CMB we
↵
2
9
h
vi
⇠
⇠
10
GeV
ann
e Universe. The neutral atoms collapse
due 2to gravitation and
(300 GeV)
e structures such as galaxy, clusters of galaxies etc.
n and relativistic particles in thermal equilibrium the density
10
27
3
1
2.5
⇥
10
GeV
3
⇥
10
cm
sec
o the 4, however non-relativistic
matter
as
T
to
the
3.
Therefore
'
'
h ann vi
h ann vi
Early Universe
Present
Universe
matter dominates
the Universe,
it is called
Radiation-Matter
onding
to 10 to 12 sec
or the1 eV of temperature.
Homogeneous,
isotropic
Inhomogeneous, anisotropic
⇢
⇠ 10
⇢
Tuesday, November 11, 14
⇢/R
4
5
⇢ ⇢
By gravitational
1⇠ 10
⇢
⇢
attraction
3
⇢ / R 16
⇢
&1
⇢
5
(1)
2
(2)
- Linear growth of the perturbation
The growth of the primordial density perturbation in the expanding
universe depends on the scale, type of matter and background matter.
⇧
⇧
log a
t
Outside horizon : density⌃ perturbation
is constant
with adiabatic condition p = p(⌅)
2/3
1 2 2 1 2 2
V = M ⌃ + m ⌥
2
2
⌃
⌥
H⇥
2⇤
P⇤ =
Inside horizon :1density perturbation grows
(1)
(2)
⇥2
(1)
H0 dL = z + (1 − q0 )z 2 + ⇧· · ·
3H 2zeq ≃ 3200
2
(3)
⇥=
⇧⌅c =
⇧
(t
,
x)
+
⌅
(t
,
x)
=
⌅
(t
r D
⇤ D
tot D )
⇧c
8⌅G
⌃ log a
t2/3
⌃ !
(1)
% Matter dom.
#
$
Radiation
dom.
⇧
−1−3ω
" ⇤ R
T2(⇤, 2⌃) T0
2
l
2⇥
=
a
Y
(⇤,
⌃)
C
=
⌥|a
|
Ṙ
Ω
R
−
(Ω
−
1)
=
H
lm
l
lm
i0
0
m
(4)(2)
ensemble
0 0T
1 2 2 1 2 2
⇧
(2)
= M ⌃ + m ⌥
⌃ 0 ⌥i
l,m R0
2/3
2/3
2
2
Non-Rel.
matter
⌃ log
a ⌃ log⌃t log aa ⌃ ta ⌃ t
⌃
1
& d(H
'2 /a)
⇧
⇧
⇤
⇥
(5)
⇤
<0⇧
ä
>
0
2 2
"
Ṙ
R
8πG
dt
0 H0
2
2 2 2
(3)
k = (Ω0 −
ρi − (Ω0 − 1)
=
⇧ 1)R0 H03H H =
2
(3)
⇥=
⇧c =matter
R
3
R
1
1
Rel.
oscillating
oscillating
2 i2 1
2 2 1
⇧
8⌅G
2 ⇥⌥
2=⇥
2⌃ 2 ⌥
V
=
M
⌃
+
m
⌃
⇤
V
=
M
⌃
+
m
⌥
⌅
r
ä > 0 ⇧
⇧
+
3p
<
0
(6)
2
2
2
2
c
=
⇤
⇧
⌃
⇧
alm Yml (⇤, ⌃)8πGCl = ⌥|alm |2 ensemble
k
1 ˙2
2
⌃ + V (⌃)
H ≃
ρ
Ω ⇧−=1 =
l,m
3
2
⇥n
d(H 1 /a)
<P0⇥ (k)
⇧ ä=>P⇥0(k0 ) k
Tuesday, November
dt 11, 14
k
1
(4)1 1
2 ⇥2
2
p = ⌃˙∝
V (⌃)R H
∝
R
k
H 2 R2
ρR2 P ⌅ (k) =
17
PT (k)⇥=(5)
PT
=
⇧
(k )
0
k
k
⇥nT
1
2⇤3H 2
⇧c ⇧=
=
(7)(4)
1
3H 2
(8)
⌃
⌥
oupled photon is the CMB we observe now from all
The neutral atoms collapse due to gravitation and
v such
+ ~v as+galaxy,
~v ) clusters of galaxies etc. (40)
tivistic particles in thermal equilibrium the density
owever non-relativistic matter as T to the 3. Theredominates the Universe, it is called Radiation-Matter
10 to 12 sec or the1 eV of temperature.
⇢
⇢
Dark Matter
Baryon
10
2 ⇥ 10
⇢
(41)
4
(1)
3
(42)
dR
<
34
3
dQ
⇥ 10 gram cm
,0 = 4.8obs.limit
dR
0
Tuesday, November 11, 14
0
18
2
(2)
Log10(scale
factor)
(43)
4. Dark matter density is small locally but
exists in the large scales. Thus they dominate
the matter density in the Universe and the
cumulative gravitational attraction affects the
dynamics of the galaxy.
19
Tuesday, November 11, 14
Dark Matter
in the present Universe
• Rotation curve of spiral galaxies
• Gravitational lensing
• Velocity dispersions of galaxies in the cluster
• Bullet cluster
20
Tuesday, November 11, 14
Hubble's map: Dark matter may be invisible but it accounts for most of the Universe's mass. Its
gravitational attraction acts as a template, pulling normal matter - the stars in their galaxy
groupings into the large-scale structures we can21see through telescopes.
Tuesday, November 11, 14
Mattertrue
around
Milkydistribution
Way
mass
of galaxie
• Image of DarkThe
The visible
portion of a
galaxy lies de
in the heart o
large halo of
dark matter.
The total mas
dark matter is
about 10x m
than in visible
material (e.g.
stars!!)
22
Tuesday, November 11, 14
1991MNRAS.249..523B
1991MNRA
(Lower luminosity galaxies)
DM
visible
gas
[Begeman, Broeils,Sanders, 1990]
23
Tuesday, November 11, 14
•
each
other
toThe
make
them
thermal
equilibrium
with
from
the
palsma.
decoupled
photon
is the
CMB
obs
We
knowinthe
fundamental
particles
ata
annihilates.
The
proton
and neutron
combine
tothe
make
light
nuclei.
At 1we
MeV,
However
the
Universe
expanding
the density
and
directions
the Universe.
Theisatom
neutral
atoms
collapse
due
t
quarks,
leptons
andand
Higgs.
They
all
existed
nuclei combine
with in
electron
to
make
neutral
theand
photons
decouple
Dark
Matter
around
Sun
in
the
Milky
Way
plasma
decreases.
So
the
transition
happens.
At
the structures
such
as
galaxy,
clusters
offrom
galaxie
from the finally
palsma.forms
The decoupled
photon
is dense
thephase
CMB
wehot.
observe
now
all 1
it was
very
and
All
the
particl
hadron
transition
occurs,
and
1
MeV
neutrinos
decouples
a
directions in The
the Universe.
The
neutral
atoms
collapse
due
to
gravitation
and
radiation
and
relativistic
particles
in
thermal
equilib
each other to make them in the thermal eq
Large
uncertainty
in
the
inner
annihilates.
The
proton
and
neutron
combine
to
makeasligh
finally forms
the
structures
such
as
galaxy,
clusters
of
galaxies
etc.
decreases as T to the However
4, however
non-relativistic
matter
T
the Universe is expanding and
The radiationnuclei
and relativistic
particles
inofthermal
equilibrium
density
combine with
electron
to make
neutral the
atom
and th
part
galaxies.
fore
at
some
point
matter
dominates
the
Universe,
it
is
called
plasma
decreases.
So
the
phase
transition
decreases as T to the
however
non-relativistic
matterphoton
as T to is
thethe
3. CMB
Therefore
from4, the
palsma.
The decoupled
we o
corresponding
to Universe,
10 to 12 itsec
or
the1
eV1 of
temperat
hadron
transition
occurs,
and
MeV
neutr
at some equality
point matter
dominates
the
is
called
Radiation-Matter
directions in the Universe.
The
neutral
atoms
collapse
du
Around
Sun
equality corresponding
10 to
12 sec
or the1
eV
of
temperature.
annihilates.
The
proton
and clusters
neutronofcomb
finallytoforms
the
structures
such
as galaxy,
galax
3
⇢
'
0.3
±
0.1
GeV
cm
nuclei and
combine
with particles
electron intothermal
make neut
The radiation
relativistic
equ
from
the
palsma.
The
photon
is
decreases
as
T
to
the
4,
non-relativistic
matter
as
3 however
25 decoupled
3
(1)
⇢DM (Sun) ⇠ 0.3 ± 0.2 GeV/ cm ⇠ 5 ⇥
10
gram/ cm
v
⇠
const.
fore at somedirections
point matter
the Universe,
it is calle
in dominates
the Universe.
The neutral
at
Important
for
direct
and
indirect
equality corresponding
to
10
to
12
sec
or
the1
eV
ofgalaxy,
tempe
↵2R(t
finally
forms
the
structures
such
as
)
2
9
0
(2)
h ann viz⇠+ 1 = detection
⇠ 10 GeV
1Mpc
⇠
1Mp
2
f
f
(300
GeV)
The
radiation and relativistic particles
R(t)
decreases as TNumber
to thedensity
4, however non-relativ
✓
◆
10
27
3
1
some 3point
matter
the Univ
2.5 ⇥ 10 at GeV
⇥ 10 Z
cm
0.3 1 GeV
⇢ secdominates
r
(3)
'
'
n=
⇠ 02 3
0
vi
equality
corresponding
tocm
10
or th
dr to
/M
r12
/
vh =annconst.
M =h ann
⇢(r )r
Mvi
dm
dmsec⇢(r)
0
r
F = nv
3
2
⇢
⇢
GM
m
mv
GM
5
⇢
(Sun)
⇠
0.3
±
0.2
GeV/
cm
Air
density
DM
16 at 2sea level
1 (4)
⇠ 10
1
⇠
10
(m
sec
sr
GeV)
=
v
/
⇢
2 ⇢
r
Tuesday, November 11, 14
⇢air ⇠ r10 3 gram/ cm3r
v ⇠ 100 km/ sec
v 24 ⇠ 220 km/ sec
v ⇠ 30 km/ sec
2
↵
4
3
3
5. Dark matter show their existence in
the cluster scales by gravitational
interaction.
25
Tuesday, November 11, 14
Under
supposition
that the
Coma
systemcan
has
reached,
mechanivariation
of2000
velocities
the following
considerations
be
made:
at least 1.1500
tothe
km/sec.
In
the
context
of
this
enormous
II. the
EVIDENCES
OFComa
DARK
MATTER
1. Under
supposition
that
the
system
has reached, mechanically, a stationary
state,
the Virial
Theorem
implies
velocities
the
following
considerations
can
be
made:
cally,
a
stationary
state,
the
Virial
Theorem
implies
• DM in the cluster
1
r the supposition that the Coma
has reached, mechaniϵk = −system
ϵ,
(4)
2 p1
First hints of dark
matter
from the
dispersion
of galaxies
in the
ϵk =velocity
− 2 ϵpmatter
,
The
local
dark
density
is (4)
determined
ionary
state,
the
Virial
Theorem
implies
222
Coma
where cluster.
ϵ and ϵ [Zwicky,
denote average
1933] kinetic and potential energies, e.g. of the
k
p
3 potential energies, e.g. of the
where ϵk 0.43(0.11)(0.10)
and222
ϵp denote average
kinetic
and
GeV/
cm
unit of mass in the system. For the purpose. of estimation we assume that
unit of mass in the system.1 For the purpose of estimation we assume that
Virial
Theorem
ϵ
=
−
ϵ
,
(4)
the222
matter
in
the
cluster
is
distributed
uniformly
in
space.
The
cluster
has
a F. Zwicky
k
p
2
Virial
Theorem
the matter in the cluster is distributed uniformly in24space. The cluster has a
This
implies
the
total
potential
ener
cm)
and
contains
800
radiusradius
R of about
one
million
light-years
(equal
to
10
24for
This
implies
for
the
total
potential
energy
Ω:
contains 800
R of about one million light-years (equal to 10 cm) and
99
nebulae
with
a mass
of each
corresponding
toto 10
solar
masses.
individual
nebulae
with
a
mass
of
each
corresponding
10
solar
masses.
ϵp individual
denote
average
kinetic
and
potential
energies,
e.g.
of the
1
This implies for the total potential energy Ω:
2
The mass
M ofMthe
system
is therefore
3 k iM=
3
The mass
of whole
the whole
system
is therefore
hE
hU i
d
Ω = we
− Γassume
s in the system. For the purpose of estimation
that
2
Ω
=
−
2
F.
Zwicky
5
R
9 9
33 333 M
4545
×
2
×
10
=
1.6
×
10
g.g. cluster has
(5) a
M
∼
800
×
10
×
2
×
10
=
1.6
×
10
(5)
M
∼
800
×
10
Ω=−
Γ
(6) 5
n the cluster is distributed uniformly
in5 space.
The
R Gravitational constant
Γ24=
implies one
for the
total potential
energy (equal
Ω:
800
about
million
light-years
to 10 cm) and contains
Gravitatio
Γ=
Γ = Gravitational constant9
nebulae with a massorof each
to 10 solar masses.
2
3 Mcorresponding
12
( cm2 s−2
Ω
=
−
Γ
(6)
ε
=
Ω/M
∼
−64
×
10
or
p
R = 10 24) cm
or
M of the whole
system is therefore
5 R
12
2 −2
ε
=
Ω/M
∼
−64
×
10
cm
s
εp = Ω/M ∼(7)
−64
and thenp
constant
Γ = Gravitational
12
2 −2
9
33
2 /2 45
ε
=
v
∼
−ε
/2
=
32
×
10
cm
s
k × 10
p
1.6
g.
(5)
M and
∼ 800
then× 10 × 2 × 10 =and
then
then
12
2 −2
!
"
1/2
εk = v 2 /212∼ −ε
/2
=
32
×
10
cm
s
2 p−2
2
ε(7)
= v 2 /2 ∼ −εp /2 =
v
= 80
εp = Ω/M ∼ −64 × 10 ! cm" s
kkm/s.
1/2
2
⌧ 1000 123
km/ sec
!
"
v
=
80
km/s.
(8) eff
1/2
In order to obtain the observed value of an average Doppler
123v 2
=ha8
∼km/s
−εp /2or=more,
32 × 10
cm
s
the
average
density
in
the
Coma
system
would
Therefore
thetoaverage
density
should
be of
at an
least
100 times
larger
than
that
In order
obtain
the
observed
value
average
Doppler
effect
of 1000
! least
"1/2 400 times larger than that derived on the grounds of obse
or more,v 2the average
density
in the Coma system(8)
would have to be at
fromkm/s
the observations
of
luminous
matter.
=
80
km/s.
26
In
order
to
obtain
the
8 OF DARK MATTER observed value
III. PROPERTIES
εk =
v 2 /2
12
2 −2
If this would
begrounds
confirmed
we would getof the
luminous
matter.
least
400
times
larger
than
that
derived
on
the
of
observations
Tuesday, November 11, 14
• Gravitational lensing
Gravitational lensing
Einstein: All forms of matter and energy cause gravity, and
are affected by gravity. By observing how light is deflected, we
can detect gravitational fields, and the distribution of matters.
The difference between the mass from the gravitational lensing and the
luminous matter gives the dark matter distribution.
27
Tuesday, November 11, 14
• Bullet cluster
Two colliding clusters of galaxies
The bullet cluster
[Clowe et.al, 2006]
(1E 0657-558)
Optical X-ray Gas Dark Matter
Gravitational potential is located in a Dark Matter (blue)
other than the ordinary matter (red)
28
Tuesday, November 11, 14
The Merging clusters give upper bound
on the self interaction of dark matter
itself.
Merging Clusters
Maruša Bradač
Challenge
hen how about the interaction is much weaker? They decouple earlier
he abundance increases. However after inflation epoch there is a highest
erature, reheating temperature, and the decoupling temperature is higher
TR, they cannot be in the thermal equilibrium, which means that Y is much
er than that in TE. However they can give correct Y for dark matter. That
2g−1
2g−1
2g−1
σ/m
<
3
cm
σ/m
<
0.7
cm
σ/m
<
4
cm
WIMP for dark matter, and the Y depends on the Tr after inflation. Even
Bradač
al. 2008
et al. 2011
Randall etisal.extremely
2008
h interaction
weak,etstill
they can beMerten
dark matter
without any
em.
σ/m < 7 cm2g−1
σ/m < 3 cm2g−1
he popular example
of E-WIMP is gravitino
and
Dawson et
al. axino.
2012
Clowe et al. 2012
Will we ever do better?
m≫T
σ/m ! 10−24 cm2 / GeV
(1)
σ/m < 0.05 cm2g−1 will be effectively
the same as CDM in terms
29
Tuesday, Novemberof
11, 14observables of structure (halo profiles, shapes, substructure
about the interaction is much weaker? They decouple earlier
dance increases. However after inflation epoch there is a highest
reheating
temperature,
the decoupling
Dark
Matter as aand
particle
must (be) temperature is higher
y cannot be in the thermal equilibrium, which means that Y is much
hat in1.TE.
However
give
correct up
Y for
dark matter. That
have
existed they
fromcan
early
Universe
to now
or darkand
matter,
and
the Ygalaxies,
dependsclusters
on the Tr after inflation. Even
located
around
ction is extremely weak, still they can be dark matter without any
stable or lifetime longer than the age of universe
ar example
of E-WIMP
is gravitino and
axino.
2. neutral
: NO electromagnetic
interaction
11
Wednesday, June 5, 13
Only upper bounds on the self interaction
m≫T
σ/m ! 10−24 cm2 / GeV from bullet cluster(1)
No lower bound down to gravity!
In fact all the evidences are gravitational.
−2
−10
−38
2
(2)
h2W IMP
=≃
⟨σ
⟩
≃
10
GeV
≃
10
cm
ann
3. 25% of the present
energy density of the universe
!
"#
$ the structure formation
4. cold
(or
warm)
:
non-relativistic
to
seed
Y
m
2
Ωh = m n ≃ 0.28
(3)
−11
10
100 GeV
30
Tuesday, November 11, 14
where ρ0 and the radius(1)
Rs vary f
τ
∼
1
sec
−10
sec
X
matter consists of particles which are relativistic at the
parameters
α, dark
β and γ vary slight
regions above the free-streaming scale.
This hot
where
ρ
me of structure formation and therefore
lead
to
large
0
m
ã
other.
The
four
most
popular
ones
2
2
matter
consists
ofΩparticles
which
ΩX h are relativistic at the
(2)
ã h =
paramet
amping
scales
(Bond
and
Szalay,
1983).
Dark matter
candidate
in
the
Standard
Model?
m
X
timeare
of the
structure
therefore lead to large
The SM neutrinos
simplestformation
examples and
of hot
other.
T
•
Navarro,
Frenk
and
W
10
! decoupled
damping
scales
(Bond
Szalay,
1983).
(3)
G
!
a
fa ∼ 10 GeV
U (1)Yuniverse
SUthey
(2)Lcanand
ark matter. In the
early
be
file
(Navarro et al., 1997),
The
only
EM
neutral
and
stable
particles,
neutrino,
was
a
candidate
The
SM
neutrinos
are
the
simplest
examples
of hot
om a relativistic bath at T ∼ 1 MeV, leading to a relic
3, γ = 1, and Rs = 20 Kpc.
• Na
for
hot
dark
matter.
bundance todaydark
that matter.
depends on
the
sum
of
the
flavor
In the early universe they can be decoupled
file
masses:
from a relativistic bath
at20T−∼251 MeV, leading to a relic
x
∼
(4) et 3,
f
•
Moore
profile
(Moore
al.γ
!
Neutrinos
decouple
from
a
relativistic
thermal
bath
at
T~
1
MeV
in
the
abundance
today that depends on the sum1.5,
of the
flavor
2
i mνi
β
=
3, γ = 1.5, and Rs
.
(188)
Ω
h
=
ν
early Universe
relic density today as
masses:with
90aeV
!
• Mo
• Kra profile (Kravtsov et al.
1.5
#5
(188)
2, β = 3, γ = 0.4, and Rs =
arious observational constraints combining
Ly-α
mforνi
2
i
" leads.
Ων h =data
st, CMB, SuperNovae and Galaxy
Clusters
!90 eV
64π
fa
40
(5)
τa ∼et al.,
sec
≃ 10
o (Fogli et al., 2008; Seljak
2006):
mν10 <
2
3
gaγγ m
10 to
GeV
a
•
Kr
.17 eV (95 % CL).
Similar
limits
can
be
applied
Various
observational
constraints
combining
Ly-α
for•
Modified
Isothermal
profi
With observational constraints
$
ny generic hot est,
darkCMB,
matterSuperNovae
candidate, such
as ax- Clusters
2,
1998),
where
α
=
2,
β
=
and Galaxy
data
leads
!
mhot
eV neutri(95% CL)
(6)
It
is
too
small!
ν < 1.3
ons (Hannestad to
et al.,
2010)
or
to
sterile
3.5
Kpc.
(Fogli et al., 2008; Seljak et al., 2006):
mν <
os (Dodelson et al., 2006; Kusenko, 2009). The
free- et al., 2011]
[Komatsu
ρDM
−29
−3limits can be
2 (95
2
0.17
eV
%
CL).
Similar
applied
• Mo
ρc =for
3H0neutrinos
MP = 1.88is ×(Kolb
10 and
g cmTurner, ΩDM =
∼ 0.22 to
(7)
treaming length
Amongst
the
four profiles, th
ρc all
any
generic
hot
dark
matter
candidate,
such
as
ax199
988):
The fluctuations are damped smaller than the neutrino
free
streaming
scale(the inn
tions
are
most
pronounced
ions (Hannestad
sterile neutri3.5
"
# et al., 2010) or to hot
also
the
most
compromised
by
nu
30
eV
nos
(Dodelson
et
al.,
2006;
Kusenko,
2009).
The
free18
+
λFτS ∼ 20
Mpc.
(189)
power-law
index
value,
γ, in th
It10is26too
hot! ZThe
top-down
structure
formation
τDM >
∼
10
sec
τ
>
sec
e
,
p̄,
γ,
.
.
.
(8)
age
DM
2
streaming mlength
for neutrinos is (Kolb
Turner, uncertainties
ν
part of and
the numerical
Amon
1988):
as all four simulations provide
di
tions
are
or instance, the universe dominated
by
the
eV
neutri(3)C × SUformation
(2)L × U (1)
(9)
Y
The standard theory SU
of structure
prefers
to
cold
dark
matter.
simulations
hint
towards
aalso
cuspy
pr
#
os would lead to suppressed structures at 600 "
Mpc
scale,
the
31
30
eV
−3inner regions becomes large, w
the
oughly
the
size
of
supercluster.
Furthermore,
hot
dark
(T
≫
m)
(T
≪
m)
n
∝
a
λ
∼
20
Mpc.
(189) (10)
The pow
FS
Tuesday, November 11, 14
• Candidates of dark matter
: Motivated from beyond Standard Model
Strong CP problem : axion
Neutrino sector : sterile neutrino, RH neutrino, Majoron
Technicolor : Techni-baryon, Techni-dilaton
Supersymmetry : neutralino, gravitino, axino, scalar neurino
Extra dimension : Kaluza-Klein particle
and WIMPzillas, Balck-Holes, light volume moduli, dilaton
and more ....
32
Tuesday, November 11, 14
axino
TP
axino a
Y
log10(σint / pb)
could
draw
the isplot
of Y
and the mass. For light
ass
range.
That
called
warm
Y is• constant
changes
forStandard
the mass
Candidates ofand
dark matter
beyond
Model above MeV and
0
0
10
rtional
to cubic
thegood
mass.
The line of relic density
keV mass
can beofthe
can-1
10
neutrino ν
it is overproduced
and ruled out. For heavy-2
-5
heAbove
free-streaming,
cosmological
10
WIMP
-3
must
besignificantly
larger -10
than suppressed.
around
2
GeV,
and
this
is
called
ring is
10
neutralino χ
-4
10
GeV particles with weak interaction, the relic density
-5
-15
10
Interaction
or
$ dark matter, it is the WIMP. Yes there is another
10-6
-20
40
-7
s with
around
keV mass range.
That is called warm
10
10
(1)
~
axion a
-25
Sterile
neutrino N
10
-8
-9
r sterile neutrinos with keV mass can be the good can--10
-30
10
13
100 GeV
eV ∼the
100free-streaming,
GeV
10 GeV
at scales
smaller than
cosmological
-11
10
gravitino g
-35
-12
and gravitational clustering is(2)
significantly suppressed.
10
10
3/2
-40
−9
!
µeV
keV
GeV
-18 -15 -12 -9 -6 -3 0 3 6 9 12 15 18
log10(mDM / GeV)
#
$
(3)
≃ 10 m " 106.75
2
40
Mass 3310
≃
1 keV
g∗
Tuesday, November 11, 14
MGUT
10
-13
10-14
10
-15
(1)
10
• Astrophysical phenomena
Cosmic rays: charged heavy particles
X-ray, gamma ray, radio ...
Neutrinos
• What are the sources of these signatures?
Supernovae, Gamma-ray burst, AGN, pulsar, DM, .....
34
Tuesday, November 11, 14
E2dN/dE
(GeV cm-2sr-1s-1)
Cosmic rays
-Astrophysical primary positron sources (ie. pulsars)
CAPRICE
-Dark matter annihilations/decays
AMS
0
BESS98
protons only
10
Ryan et al.
Grigorov
JACEE
Akeno
Tien Shan
all-particle
MSU
10-2 electrons
KASCADE
CASA-BLANCA
DICE
HEGRA
positrons
CasaMia
Tibet
-4
Fly Eye
10
Haverah
Yakutsk
AGASA
HiRes
10-6
Cosmic ray
Aguilar et al.,
positron
access
PRL ’13
AMS-02
+
(e ) / (
-Reacceleration of secondary
Most importantly, several independent analyses were
performed on the same data sample by different study
groups. Results
these analysesremnants
are consistent with those
positrons
near of
supernova
presented in Fig. 5 and in Table I (see also [13]).
Positron fraction
  Proposed solutions include:
0
PAMELA
Fermi
0
-1
10
Secondary
Background
1
10
102
(Torsten Bringmann)
antiprotons
FIG. 5 (color). The positron fraction compared with the most
recent measurements from PAMELA [22] and Fermi-LAT [23].
The comparatively small error bars for AMS are the quadratic
sum of the statistical and systematic uncertainties (see Table I
and [13]), and the horizontal positions are the centers of
each bin.
10-8
14110
10-10 0
10
102
104
106
108
1010
Ekin (GeV / particle)
35
Tuesday, November 11, 14
PRELIMINARY
Super−K
t
en
nv
co
−3
IceCube µ
unfolding
forward folding
µ
l
na
io
10−4
l
na
io
10
e
−5
10
This Work
µ
Fr ejus µ
Fr ejus e
AMANDA µ
unfolding
forward folding
10−2
t
en
E2
10−1
nv
co
[GeV cm−2 s−1sr−1]
Atmospheric Spectrum
e
−6
10
10−7
−8
10
−9
10 −1
prom
Honda
Bartol
Honda
0
pt
µ
µ,
e
e
e
1
2
3
4
5
6
7
log (E [GeV])
10
PRL 110 (2013) 151105
N. Whitehorn, UW Madison
Tuesday, November 11, 14
36
IPA 2013 - 8
E2ν dNν /dEν [GeV cm-2 s-1 sr-1]
Interesting Neutrinos above 1 TeV
10-2
Honda 2006 Atmos. ν µ
10-3
Sarcevic Prompt Atmos. ν µ
-4
Waxman Bahcall 1998 × 3/2
10
GZK Neutrinos
IC40 Atmos. ν µ Unfolding
10-5
10-6
10-7
10-8
10-9
10-10
103
104
105
106
107
108
109
1010
1011
1012
Eν [GeV]
I
⇡/K Atmospheric Neutrinos (dominant < 100 TeV)
I Charm Atmospheric Neutrinos (“prompt”, ⇠ 100 TeV)
I Astrophysical Neutrinos (maybe dominant > 100 TeV)
I Cosmogenic Neutrinos (> 106 TeV)
N. Whitehorn, UW Madison
37
Tuesday, November 11, 14
IPA 2013 - 2
Gamma rays
Dan Hooper – Indirect Searches For Dark Matter
The Backgrounds
Astrophysical sources of gamma rays consist of:
1) Pion production (cosmic ray protons/nuclei colliding with gas)
2) Inverse Compton Scattering (cosmic ray electrons up-scattering starlight/CMB)
3) Bremsstrahlung (cosmic ray electron interactions with nuclei)
4) Point sources (supernova remnants, pulsars, blazars, etc.)
GALPROP defaults, inner galaxy
13
FIG. 9: The predicted spectral shapes of gamma rays from pion decay, inverse Compton scattering, and Bremsstrahlung in the
region around the Galactic Center, as generated using the publicly available code GALPROP [16].
38
Tuesday, November 11, 14