Comoving number density

Gravitationslinsen Rotationskurven

Indirekter Nachweis der DM

( Annihilation der DM in Materie-Antimaterie)

Direkter Nachweis der DM

( Elastische Streuung an Kernen)

Nachweismethoden der DM

Gravitationslinsen

ART: Die Ausbreitung von Licht ändert sich

beim Durchgang durch

ein Gravitationsfeld

Gravitationslinsen

Colliding Clusters Shed Light on Dark Matter

Observations with bullet cluster:

•Chandra X-ray telescope shows distribution of hot gas

•Hubble Space Telescope and others show distribution of dark matter from weak gravitational lensing

•Distributions are clearly different after collision->

dark matter is weakly interacting!

Rot:sichtbares Gas

Blau: dunkle Materie aus Gravitations- potential

dunkel

http://www.sciam.com/

August 22, 2006

Simulation der “Colliding Clusters”

Center of the Coma Cluster by

Hubble space telescope ©Dubinski

Discovery of DM in 1933 Zwicky, Fritz (1898-1974

Zwicky notes in 1933 that

outlying galaxies in Coma cluster moving much faster than mass calculated for the visible

galaxies would indicate

DM attracts galaxies with more force->

higher speed.

But still bound!

Dunkle Materie im Universum

Die Rotationskurven von

Spiralgalaxien sind weitgehend flach, während die leuchtende Materie eine abfallende Kurve erwarten lässt. Erklärung: dunkle Materie.

Spiralgalaxien bestehen aus einem zentralen Klumpen und einer sehr dünnen Scheibe

leuchtender Materie, welche von einem nahezu sphährischen,

sehr ausgedehnten Halo umgeben

Messung der Masse durch Newtons Gravitationsgesetz v=ωr

v ∝ 1/ √ r

mv

/r=GmM/r

Milchstraße

Cygnus Perseus

OrionSagittarius

Scutum Crux

Norma

Sun (8 kpc from center

Do we have Dark Matter in our Galaxy?

Rotationcurve Solarsystem

rotation curve Milky Way

∝1/√r

Estimate of DM density

DM density falls off like 1/r

for v=const.

Averaged DM density “1 WIMP/coffee cup”

(for 100 GeV WIMP)

• Für Ensemble wechselwirkender Systeme im mechanischen Gleichgewicht gilt

• Für N Teilchen, also N(N-1)/2 Teilchenpaaren

Für N groß: und

0 2 E

+ E

=

2 0 ) 1

( ²

2 − − =

r N m

G N v

m N

( ^{N − 1} ) ^{≈ N}

v M r

m Nx

2 2

≈

⇒ =

2 2

m m =

Erwarte also für ´Gas` gravitativ

wechselwirkender Teilchen M ∝ r ! Aber dann:

v

∝ M/r = konst -> flache Rotationskurve

Virialsatz

Expansion rate of universe determines WIMP annihilation cross section

Thermal equilibrium abundance Actual abundance

T=M/22

Comoving number density

x=m/T

Gary Steigmann/ Jungmann et al.

WMAP -> Ωh²=0.113±0.009 ->

<σv>=2.10^-26 cm³/s DM increases in Galaxies:

≈1 WIMP/coffee cup ≈10⁵ <ρ>.

DMA (∝ρ²) restarts again..

T>>M: f+f->M+M; M+M->f+f T<M: M+M->f+f

T=M/22: M decoupled, stable density (wenn Annihilationrate ≅ Expansions- rate, i.e. Γ=<σv>nχ(x_fr) ≅ H(x_fr) !)

Annihilation into lighter particles, like quarks and leptons -> π₀’s -> Gammas!

Only assumption in this analysis:

WIMP = THERMAL RELIC!

10^-9s

• 95% of the energy of the Universe is non-baryonic

23% in the form of Cold Dark Matter

• Dark Matter enhanced in Galaxies and Clusters of Galaxies but DM widely distributed in halo->

DM must consist of weakly interacting and massive particles -> WIMP’s

• Annihilation with <σv>=2.10^-26 cm³/s, if thermal relic

From CMB + SN1a + surveys

DM halo profile of galaxy cluster from weak lensing

If it is not dark It does not matter

What is known about Dark Matter?

Kandidaten der DM

Problem: max. 4% der Gesamtenergie

des Univ. in Baryonen nach CMB und BBN.

Sichtbar nur 0.5%, d.h. 3.5% in obigen Kandidaten möglich. Rest der DM muss aus nicht-baryonischen Materie bestehen.

Probleme:

•Ω_ν < 0.7% aus WMAP Daten kombiniert mit Dichtekorrelationen der Galaxien.

•Für kosmische Strings keine Vorhersagekraft.

•Abweichungen von Newtons

Gravitationsgesetz nicht plausibel.

•WIMPS ergeben nach Virialtheorem flache Rotationskurven.

In Supersymmetrie sind die WIMPS Supersymmetrische Partner der CMB d.h. Spin ½ Photonen (Photinos genannt).

†

†

?

?

Simple 3-Component Galaxy: p+e+Wimps

Interactions:

p+e <->H electromagnetic x-section

p+p -> X strong x-section: 10

cm

p+W -> p+W x-section:<10

cm

(direct DM searches) W+W -> X x-section: 10

cm

(Hubble expansion)

These cross sections are exactly

order of magnitude predicted by SUSY!

Example of DM annihilation (SUSY)

Dominant

χ + χ ⇒ A ⇒ b bbar quark pair Sum of diagrams should yield

<σv>=2.10^-26 cm³/s to get correct relic density

Quark fragmentation known!

Hence spectra of positrons, gammas and antiprotons known!

Relative amount of γ,p,e+ known as well.

χ χ

χ χ

χ χ χ

χ

χ χ f

f

f

f

f

f

Z

Z W

χ^± W χ⁰

~f

A Z

gammas≈37

Indirect Dark Matter Searches in the Light of ATIC, FERMI, EGRET and PAMELA

Annihilation products from dark matter annihilation:

Gamma rays

(EGRET, FERMI)

Positrons

Antiprotons

e+ + e-

(ATIC, FERMI, HESS, PAMELA)

Neutrinos

e-, p drown in cosmic rays?

IF DM particles are thermal relics from early universe they can annihilate with cross section as large as

< σ v>=2.10

cm

/s

which implies an enormous rate of gamma rays

from π

decays (produced in quark fragmentation) (Galaxy=10

higher rate than any accelerator) Expect significant fraction of energetic

Galactic gamma rays to come from DMA in this case.

Remaining ones from p

+p

-> π

+X ,

(+some IC+brems)

This means: Galactic gamma rays have 2 components

with a shape KNOWN from the 2 BEST studied reactions in accelerators: background known from fixed target exp.

DMA known from e+e- annihilation (LEP)

Conclusion sofar

Anmerkungen zur indirekten Suche nach DM Gamma rays:

•keine Ablenkung durch das Galaktische Magnetfeld

• zeigen daher in Richtung der Quelle

•kaum Abschwächung in der Galaxie bei GeV Photonen

• Astrophysikalische Quellen als Punktquellen erkennbar und können daher subtrahiert werden

• Untergrund hat anderes (aber bekanntes) Spektrum als DMA Signal.

Durch gleichzeitiges Fitten von Form des Spektrums für

Signal und Untergrund können beide Beiträge direkt aus den Daten bestimmt werden, wenn man die Normierung als freier Fitparameter behandelt (data driven analysis)

Geladene Teilchen:

•Ablenkung durch das Galaktische Magnetfeld, sie zeigen daher nicht in Richtung der Quelle

•Wahrscheinlichkeit, dass z.B. Antiproton aus DMA im Detektor ankommt, stark abhängig vom Propagationsmodell

•Keine Trennung von astrophysikalischen Punktquellen möglich

Woher erwartet man Untergrund?

Quarks fromWIMPS

Quarks in protons

Background from nuclear interactions (mainly p+p-> π0 + X -> γ + X inverse Compton scattering (e-+ γ -> e- + γ)

Bremsstrahlung (e- + N -> e- + γ + N)

Shape of background KNOWN if Cosmic Ray spectra of p and e- known

Energy loss times of electrons and nuclei

Protons diffuse for long times without loosing energy!

τ ^-1 = 1/E dE/dt

τ

If centre would have harder spectrum, then hard to explain why excess in outer galaxy has SAME shape (can be fitted with same WIMP mass!)

Usual astrophysicist’s search strategies

Particle physicist: get rid of model

dependence by DATA DRIVEN calibration

Instrumental parameters:

Energy range: 0.02-30 GeV Energy resolution: ~20%

Effective area: 1500 cm² Angular resol.: <0.5⁰

Data taking: 1991-1994 Main results:

Catalogue of point sources Excess in diffuse gamma rays EGRET on CGRO (Compton Gamma Ray Observ.)

Data publicly available from NASA archive

Two results from EGRET paper

Enhancement in ringlike structure at 13-16 kpc

Called “Cosmic enhancement

Factor”

Excess

1 10 Eγ GeV

Untergrund + DM Annihilation beschreiben Daten

Blue: background uncertainty

Background + DMA signal describe EGRET data!

Blue: WIMP mass uncertainty 50 GeV

70

Brems . WIMPS IC

π

π

0 WI

MPS Brems

. IC

W. de Boer et al., 2005

Analyse der EGRET Daten in 6 Himmelsrichtungen

A: inner Galaxy (l=±30⁰, |b|<5⁰) B: Galactic plane avoiding A

C: Outer Galaxy

D: low latitude (10-20⁰⁾

E: intermediate lat. (20-60⁰) F: Galactic poles (60-90⁰)

A: inner Galaxy B: outer disc C: outer Galaxy

D: low latitude E: intermediate lat. F: galactic poles

Total χ² for all regions :28/36 ⇒ Prob.= 0.8 Excess above background > 10σ.

EGRET Excess predicts shape of rotation curve!

Outer Ring Inner Ring

bulge disk

Rotation Curve

Normalize to solar velocity of 220 km/s

R₀=8.3 kpc R₀=7.0

v

R/R₀ Inner

rotation curve

Outer RC

Black hole at centre:

R₀=8.0±0.4 kpc

Sofue &Honma

Note 1: Absolute value of rotation curve depends on distances.

But chance of slope can ONLY

be explained by ringlike structure.

Note 2: fact that shape of DM halo can describe shape of RC implies

that EGRET excess has exactly right intensity to deliver grav. potential!

Gas flaring in the Milky Way

no ring

with ring

P M W Kalberla, L Dedes, J Kerp and U Haud, http://arxiv.org/abs/0704.3925

Gas flaring needs EGRET ring with mass of 2.10¹⁰M !

Enhancement of inner (outer) ring over 1/r² profile 6 (8).

Mass in rings 0.3 (3)% of total DM

Inner Ring coincides with ring of dust and H₂ ->

gravitational potential well!

H₂

4 kpc coincides with ring of neutral hydrogen molecules!

H+H->H₂ in presence of dust->

grav. potential well at 4-5 kpc.

FERMI measures GeV gamma rays + electrons

e

e

γ

Published FERMI data

on VELA pulsar:

agrees within errors with EGRET at 3 GEV astro-ph/0812.2960

20% EGRET

Diffuse gamma rays from FERMI

100%

Why diffuse spectrum disagrees 100% with EGRET at 3 GeV while VELA spectrum agrees with EGRET at 3 GeV within 20%?

Indirect Dark Matter Searches using charged particles

Annihilation products from dark matter annihilation:

Gamma rays

(EGRET, FERMI)

Positrons

Antiprotons

e+ + e-

(ATIC, FERMI, HESS, PAMELA)

Neutrinos

e-, p drown in cosmic rays?

Resurs Dk1 Satellite

300 -600 km

Bottom Scintillator Transition

Radiation Detector

(removed for tech.reasons)

Time of Flight Counters

Silicon

Tracker and Permanent Magnet

Si-W

Electromagnetic Calorimeter

Neutron Detector Anticoincidence

Shield 1.2 m

20.5 cm²sr

~450 kg

~10 T

The PAMELA Satellite Experiment (launched July 2006)

Positron fraction

PAMELA, positron and antiproton measurements

Positrons: excess

Nature 458:60,2009,arXiv:0810.4995

Antiprotons: NO excess

Antiproton/proton ratio

+prelim. new data, Boezio, Pamela-WS 2009 (O. Adriani et. al., PRL (2009)[0810.4994])

ATIC Balloon experiment, Nature 2008

Kaluza-Klein DM decays to

lepton pairs ->peak in electron

spectrum with tail from energy losses

Baltz, Hooper, hep-ph/0411053 Hooper, Zurek, 0902.0593

KK x-section ∝ Y⁴ so mainly decay to leptons and u-quarks

Alexander Moiseev Pamela workshop

May 11, 2009

FERMI electron spectrum: NO BUMP at 600 GeV

Simulating the LAT response to a spectrum with an “ATIC-like” feature:

This demonstrates that the Fermi LAT would have been able to reveal

“ATIC-like” spectral feature with high confidence if it were there.

Energy resolution is not an issue with such a wide feature

HESS MAGIC

Cherenkov telescopes measure TeV gamma rays

HESS, May 2009

Electron spectrum falls off above 1 TeV

Interpretations for charged particle anomalies Many possibilities:

¾ Background from hadronic showers

with large electromagnetic component ->

¾ astrophysical sources

™

pulsars ->

™ positron acceleration in SNR ->

™ locality of sources ->

¾ dark matter annihilation -> a_DMA

™ leptophilic?

™ bound states?

™ Kaluza-Klein

Truth?

Depends on whom you ask!

My assumption:

|Data>= a_p->π0 |Background> + a_DMA |DMA>

+ a_sec |SNR> + a_local |SNR(x)> + a_pulsar |Pulsar>

Unitarity must be fulfilled. However, will now

show that each component has enough uncertainty

to saturate observations

a_DMA:DM interpretation of FERMI e-data

Models e.g. by

Arkani-Hamed,Finkbeiner,Slatyer,Weiner arXiv:0810.0713

Nomura and Thaler, arXiv:0810.5397

Fit by Bergstrom et al.arXiv:0905.0333 TeV DM decaying to low scale

particle, which can only decay leptonically

TeV DM forms bound state to get large boost factor via Sommerfeld enhancement

a_loc :3-component e- sources: spiral arm, disc, local

3-component structure explains e-spectrum, Pamela/Fermi anomalies and why nothing in pbar

Shaviv et al., arXiv:0902.0376,2009

e

loose energy rapidly (dE/dt ∝ E

),

hence they are “local”

It can work!

What about

Supersymmetry?

Assume mSUGRA

5 parameters: m

, m

, tanb, A, sign μ

Example of DM annihilation (SUSY)

Dominant

χ + χ ⇒ A ⇒ b bbar quark pair Sum of diagrams should yield

<σv>=2.10^-26 cm³/s to get correct relic density

Quark fragmentation known!

Hence spectra of positrons, gammas and antiprotons known!

Relative amount of γ,p,e+ known as well.

χ χ

χ χ

χ χ χ

χ

χ χ f

f

f

f

f

f

Z

Z W

χ^± W χ⁰

~f

A Z

gammas≈37

Expected SUSY mass spectra in mSUGRA for EGRET WIMP mass of 60 GeV

mSUGRA: common masses m₀ and m_1/2 for spin 0 and spin ½ particles

Annihilation cross sections in m

-m

plane (μ > 0, A

=0)

tan=5 tan=50

bb t t

ττ ^WW

bb t t

ττ ^WW

For WMAP x-section of <σv>≅2.10^-26 cm³/s one needs large tanβ 10^-24

10^-27

EGRET WMAP

M

=(4 π )

Y

v

M

=(4 π )

Y

v

M

/M

= tan β

tan ß = 20

EWSB: M_Z²/2=(m₁²-m₂² tan²ß)/ (tan²ß-1)≅ -m₂² for large tan ß Pseudoscalar Higgs: M_A² = m₁²+m₂² becomes very small if Yt≅Yb at large tb (M_t²/M_b²) = (Yt v² sin²ß)/(Yb v² cos²ß)=(Yt/Yb) tan²ß ⇒tan ß ≅ 53 for Yt≅Yb

tan ß = 51

m₂²∝ Yt m₁²∝ Yb

m₁²∝ Yb

m₂²∝ Yt

EWSB requirement leads to small M_A at large tan ß

Momentum dependence of annihilation cross section

σ=Α+Β∗v

S-wave P-wave

decoupling ns after BB

Mχ=60 GeV Mχ=50 GeV

Expected SUSY mass spectra in mSUGRA for EGRET WIMP mass of 60 GeV

mSUGRA: common masses m₀ and m_1/2 for spin 0 and spin ½ particles

Gauge unification perfect with SUSY spectrum from EGRET

With SUSY spectrum from EGRET + WMAP data and start values of couplings from final LEP data perfect gauge coupling unification!

Update from Amaldi, dB, Fürstenau, PLB 260

1991

SM SUSY

Also b->sγ and g-2 agree within 2σ with SUSY spectrum from EGRET

NO FREE PARAMETER

WdB, C. Sander,PLB585(2004).

e-Print: hep-ph/0307049

Coannihilations vs selfannihilation of DM

If it happens that other SUSY particles are around at the freeze-out time, they may coannihilate with DM.

E.g. Stau + Neutralino -> tau Chargino + Neutralino -> W

However, this requires extreme fine tuning of masses, since number density drops exponentially with mass.

But more serious: coannihilaition will cause excessive boostfactors Since

σ

= σ

+ σ

must yield < σ v>=10

cm

/s.

This means if coannihilation dominates, selfannihilation ≅ 0 In present universe only selfannihilation can happen, since

only lightest neutralino stable, other SUSY particles decayed, so no coannihilation. If selfannihilation x-section 0, no indirect detection.

χ ⁰ χ ⁰

WIMPs elastically scatter off nuclei => nuclear recoils Measure recoil energy spectrum in target

Direct Detection of WIMPs

Direct Detection of WIMPs

Direct Dark Matter Detection

CRESST ROSEBUD CUORICINO

DAMAZEPLIN I UKDM NaI LIBRA

CRESST II ROSEBUD CDMSEDELWEISS

XENON

ZEPLIN II,III,IV HDMSGENIUS

IGEXMAJORANA DRIFT (TPC)

E_R Phonons

Ionization Scintillation

Large spread of technologies:

varies the systematic errors, important if positive signal!

All techniques have equally aggressive projections for future performance But different methods for improving sensitivity

L. Baudis, CAPP2003

Wärmesignal Wärmesignal

Ladungssignal Ladungssignal Thermometer

Thermometer

Elektroden

Elektroden zur zur

Ladungssammlung Ladungssammlung

Ge Ge Kristall Kristall

bei bei T= 0,017 K T= 0,017 K

WIMP WIMP

Ge-Kern

Wärmesignal Wärmesignal

Ladungssignal Ladungssignal Thermometer

Thermometer

Elektroden

Elektroden zur zur

Ladungssammlung Ladungssammlung

Ge Ge Kristall Kristall

bei bei T= 0,017 K T= 0,017 K

WIMP WIMP

Ge-Kern

Der Edelweiss Detektor

Messprinzip eines Halbleiter-Bolometers. Kommt es zu einem elastischen Stoß eines WIMP-Teilchens mit einem Atomkern des Germanium-

Kristalls führt der Kern-Rückstoß zu einer Temperaturerhöhung des Kristalls, die über ein Thermometer registriert wird. Gleichzeitig

ionisiert der Ge-Kern das Material in seiner Umgebung, was zu einem Ladungssignal führt, das an den Oberflächenelektroden ausgelesen wird.

Der Edelweiss Detektor

Edelweiss Experiment

(in Frejus-Tunnel in französichen Alpen)

Array von

Phasenübergangs- Thermometern

Schnelle (großflächige) Auslese

von Phononen DM-Suche mit Tieftemperatur-Kalorimetern / CDMS

Sioder

GeEinkristall

Rückstoß-Energie(keV) Elektron-Rückstöße

Kern-Rückstöße

Ionisations-Energieschwelle

0 0.5

1 1.5

0 50 100 150 200

Kalibration mit ²⁵²Cf

Verhältnis Q von Ionisations- zu Rückstoß-Energie

Kalibration eines Ge-Bolometers durch Bestrahlung mit einer

252Cf-Neutronenquelle: Deutlich erkennbar sind zwei

Ereignispopulationen, die durch das Verhältnis von Ionisations- zu Rückstoß-Energie separiert

werden können. Die auf das Ionisationssignal angelegte Energieschwelle (grüne Kurve) entspricht einer Rückstoßenergie von 3.5keV. Die Bänder

beschreiben die Bereiche, in denen 90% der Elektron- bzw.

Kern-Rückstöße liegen.

Kalibration

Der Edelweiss Detektor

Der XENON 10 Detektor

Der XENON 10 Detektor

Der XENON 10 Detektor

Der XENON 10 Detektor

Comparison with direct searches

Note: N_90%CL=n_χ <σ_90%CLv>

To get σ_90%CL one has to assume v and n_χ :

v assumed Maxwellian

and NO corotation of DM halo n_χ : assume DM mass from

rotation curve to be completely diffuse.

Theory: x-section can be

order of magnitude lower due to matrix element uncertainties Conclusion: can easily move up exp. limits by order of magn.

and move down theory by order of magnitude.

Large uncertainties in direct scattering x-section

Ellis, Olive, Savage, arXiv:0801.3656

Annual Modulation as unique signature?

95 97 99 101 103 105

-0.5 -0.1 0.3 0.7 1.1 1.5

±2%

0 25 50 75 100 125

-0.5 -0.1 0.3 0.7 1.1 1.5

Background WIMP Signal

June June

Dec Dec

Annual modulation: σ ∝ v, so signal in June larger than

in December due to motion of earth around sun (5-9% effect)

June

v₀ galactic center

Sun 230 km/s Dec.

L. Baudis, CAPP2003

• DAMA NaI-1 to 4: 58k kg.day

• DAMA NaI-5 to 7: 50k kg.day

• Full substitution of electronics and DAQ in 2000

The data favor the presence of a modulated signal with the proper features at the 6.3 σ C.L.

( ⁰) ⁰

cos with t =152.5, T=1.00 y A⋅ ⎡⎣ω t−t ⎤⎦

Running conditions stable at level < 1%

DAMA/NaI 1 to 7: Riv.N.Cim 26 n.1. (2003) 1-73

Schael, EPS2003

Warum muss DM kalt sein, d.h. nicht-relativistisch?

Antwort: Aus Galaxien-

Dichteverteilung!

DM bildet Filamente erhöhter Dichte mit Galaxien und Leerräumen dazwischen

Simulation (jeder Punkt stellt eine Galaxie dar)

© Steinmeitz, Potsdam

Kriterium für Gravitationskollaps:

Jeans Masse und Jeans Länge

Gravitationskollaps einer Dichtefluktuation, wenn Expansionsrate

1/t_Exp ≅ H ≅ √Gρ langsamer als die Kontraktionsrate 1/t_Kon ≅ v_S / λ_J ist.

Oder die Jeanslänge (nach Jeans), d.h. die Länge einer Dichtefluktuation, die unter Einfluß der Gravitation wachsen kann, ist von der Größenordnung

λ_J = v_s/ √Gρ (v_S ist Schallgeschwindigkeit)

(exakte hydrodynamische Rechnung gibt noch Faktor √π größeren Wert)

Nur in Volumen mit Radius λ_J /2 Gravitationskollaps. Dies entspricht eine Jeansmasse von

M_J = 4π/3 (λ_J/2)³ ρ = (π^5/2 v_s³ ) / (6G^3/2√ρ)

Die Schallgeschwindigkeit fällt a) für DM wenn die

Strahlungsdichte nicht mehr dominiert und b) für Baryonen nach der Rekombination um viele Größendordnungen (von c/√3 für ein relat. Plasma auf √5T/3m_p für Wasserstoff)

D.h. DF die vor Rekombination stabil waren, kollabieren durch Gravitation.

Galaxienbildung in viel kleineren Bereichen möglich, wenn v_S

klein!

Abfall der Schallgeschwindigkeit nach t_r wenn Photonkoppelung wegfällt

Evolution of the universe

Early Universe

Present Universe The Cosmic screen

Jeans Masse vs. Schallgeschwindigkeit

Große Jeanslänge

(relativistische Materie, Z.B.

Neutrinos mit kleiner Masse) Kleine Jeanslänge

(non-relativistische Materie, Z.B.

Neutralinos der Supersymmetrie)

Top-down versus Bottom-up

HDM (relativistisch ⇒ v_S =c/√3) versus CDM

Oder für gemischte DM Szenarien …

Colombi, Dodelson, & Widrow 1995

Structure is smoothed out in model with light neutrinos

CDM WarmDM C+HDM

Millenium Simulation

• Was wissen wir über Dunkle Materie?

massive Teilchen

23% der Energie des Universums

schwache Wechselwirkung mit Materie Annihilation mit <σv>=2.10^-26 cm³/s

• Annihilation in Quarkpaare ->

Überschuss in galaktischen Gammastrahlen beobachtet?

Dunkle Materie, was wissen wir?

From CMB + SN1a

LHC Experimente werden ab

2010 klären ob dies stimmt.