what can we learn from cmb in the planck area? (planck is going to be launch may 6)

LHC conference - Isfahan

• Thermal History of the Universe and the standard Big-Bang model• The CMB• its origin• a tool for Cosmology• past and forthcoming observations

What can we learn from CMBin the Planck area?

(Planck is going to be launch May 6) Yannick Giraud-Héraud (APC – Paris)


• General Relativity (Einstein 1915 ; Friedmann 1922 ; Lemaître 1927)

April 21, 2009

Expansion

CMB BBNmatter dark energy curvature

The Big Bang Model


GUT?

Thermal History of the Universe and the CMB

1. inflation (1/2)

Brief period of exponential expansion(factor 1026 in ~ 10-34 s)

1) Resolve flatness, horizon, relic …problems

2) Perturbation generation- density (scalar) dm ~ EI

6/V’ ~ 10-5

- gravitational (tensor) dog ~ (EI/MPlanck)4



1. inflation (2/2)Slow roll potential, in favour today, are caracterized by 2 parameters

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ε =M p

2

16πV 'V ⎛ ⎝ ⎜

⎞ ⎠ ⎟2

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η =M p

2

8πV"V

They are related to spectral index of the density fluctuations

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ns −1 = d lnPs(k)d lnk

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nT = −2ε

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ns −1 = −6ε + 2η€

nT = d lnPT (k)d ln(k)

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r = PT (k)Ps(k)

V1/4~3.3x1016r1/4 GeV


2. nucleosynthethis

3. thermalization


LHC conference - IsfahanLarge-scale structure

2dF

theory4. temperature anisotropies



5. Energy Contents of the UniverseWhat the Universe is made of?For each component the density is defined in terms of the critical density:

Wcomposante = rcomposante/ rcritical

rcritical ~ 5. GeV/m3



6. Geometry of the Universe

flat

closed

openclosed flat open

Size of the horizonat tdec

~100 Mpc



7. Shape of the Power Spectrum (1/3)

• Primordial Universe is dominated by radiation no matter collapse

• Baryon starts to collapse at matter-radiation equality

• Acoustic waves induced by radiation pressure propagate at the speed of sound

• Oscillations are frozen at the moment of decoupling



Angular power spectrum

Statistically isotropic sky

W = 0,9 ; Wm = 0,15W = 1 ; Wm = 0,25W = 1,1 ; Wm = 0,35

l

l(l+1)/(2T C

MB2 )C

l

Spherical Harmonics Expansion(equivalent to Fourier transform)

l 1/q : l=200 q=1 deg.

Thermal History of the Universe and the CMB7. Shape of the Power Spectrum (2/3)


Thermal History of the Universe and the CMB7. Shape of the Power Spectrum (3/3)

maps power spectrum• Angular power spectrum

– ~number of fluctuations in respect to their size

• Cℓ– ℓ is inversely proportional

to the angular size ℓ=200 corresponds to q~1o


8. CMB polarisation anisotropiesLinear polarisation is due to Thomson

scattering (Rees, 1968).

The polarisation of the CMB should be small as it is

Produced by temperature anisotropies



• E modes – even parity :

• B modes – odd parity :

- E modes are produced by quadrupolar sources (density fluctuations and gravitational waves)- B modes are produced by gravitational waves and lensing of E

modes

pure E pure BWayne Hu

Thermal History of the Universe and the CMB8. CMB polarisation: decomposition in 2 modes E and B


( )17.0=τ

1.0=r

41055.6 −×=r

GeVEI16102~ ×

GeVEI15107.5~ ×

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r ≡ T 2

S2 ∝E I

M pl

⎛

⎝ ⎜ ⎜

⎞

⎠ ⎟ ⎟

4

- probe of the structure of the Universe- primordial gravitational waves: smoking gun probe of inflation

Thermal History of the Universe and the CMB8. CMB polarisation: power spectra


Key dates of the CMB observations


1) discovered at 7.35 cm (4 GHz) (Penzias & Wilson, 1964)

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T = 2.725 ± 0.002K

highly uniform

510−≈ΔTT

2) dipole ΔT= 3 mK(Smoot et al. 1976)

skmv /600≈(Mather et al. 1999 - COBE)

CMB detection history

3) Perfect black body (COBE Mather et al., 1999) 4) Anisotropies at 7o

(COBE Smoot et al. 1992)


Balloon experiments (2000-2002): Boomerang, Maxima, Archeops

17

primary

secondary

pivot

horns

bolometers

cryostat

Archeops (2002)

from COBE scale to first acoustic peak



WMAP – NASA satellite (launch 2001)

• 2 back to back telescopes• Radiometers cooled

down at 90 K• Bands at 23, 33, 41, 61 et

94 GHz• Angular resolution 13-

52’• Sensitive to polarisation• Rotation 7.57 mHz



WMAP/ACBAR power spectrum

Cosmological parameters estimation (WMAP+Acbar+CBI+Large Scale Structure Observations)

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Wo =1,020,020,02

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WΛ =0,73−0,04+0,04

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Wbh2 = 0,023−0,001+0,001

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h = 0,74−0,03+0,03

ns = 0.948+-0.25t = 0.091+-0.009

R<0.2


Planck: an ESA satellite CMB anisotropies measurements

(temperature and polarization)

International collaboration: European Community (Germany, Denmark, Spain, Finland, France, Italy, Irland, Netherland, UK, Sweden), Canada, Norvege, Switzerland, USA


Plancklaunch scheduled May 6

Herschel


Planck is going to orbit around the 2nd

Lagrangian point of the Sun-Earth-Moon system

• the sky will be scanned in 6 months• the mission is expected to last 30 months


Low Frequency Instrument (LFI) Frequencies: 30 - 70 GHz Wavelengths: 1cm - 5 mm radio detectors (22) Temperature: 20 K (Front-end), 300 K

(Back-end) Angular resolution: 12' (70 GHz) à 33'

(30 GHz) Sensitivity @30 GHz: ~5.4 mK; @70

GHz: 12.7 mK PI: N. Mandolesi (CNR –

Bologna/Italy) IS: M. Bersanelli (U. Milano/Italy)


High Frequency Instrument (HFI)

Frequencies: 100 - 860 GHz Wavelenghts: 3mm à 400µm Detectors: 52 bolometers Temperature: 0.1 K Angular resolution: 5' (850 GHz) à 9.2' (100 GHz) Sensitivity @100 GHz: ~ 5mK PI: J.L. Puget (IAS - Orsay) IS: J.M. Lamarre (LERMA – Paris)


Thermal Architecture of Planck HFI

4K

1.6K

0.1K18K

Bolomètres


Bolometers “Spider web”(Caltech/JPL)

121 Bolometers on a Wafer

857 GHz BolometerNTD Germanium


Frequency Observations

• Large bandwith coverage : 9 bands

This will allow to subtract foregrounds to the CMB

• Polarization measurement


High Angular Resolution (5’ for Planck and 7o for COBE)


High precision temperature measurement

COBE Planck

PlanckWMAP (8 ans)

~ 20 x WMAP sensitivity

Planck will have:

~ 3 x angular resolution


Main Planck Scientific Goals• for temperature measurements : definitive measurements up to

l=2000 only limited by photon noise of the CMB (astrophysical foregrounds become the major source of uncertainty)• CMB polarization measurements will be the challenging part of

Planck for E mode up to l=1000

Impact on the knowledge of the Big Bang model and on

Fundamental Physics• cosmological parameters at the % level• first constraints on inflation• Study of the large scale structure will be adressed through :• Sunyaev-Zeldovitch survey : 10000 clusters as good tracers of

the dynamics of the Universe

• B polarization measurement• study of the Milky Way• limit on neutrino mass


Planck simulated maps


Temperature Power Spectrum

l l

• Power spectrum measurement up the 8th acoustic peak

• Just cosmic variance limited up to l ~2500


Polarisation Power Spectra

Cross-spectrum TE (t=0.17)


EE spectrum (t=0.17)Adding EE power spectrum to TT power spectrum will help to reduce the degeneracy to determine the cosmological parameters

Polarisation Power Spectra


Cosmological Parameters

Planck

WMAP

• Improvment of the knowledge of the cosmological parameters

Ex: Ωb précision 10 times better than with WMAP.

• Degeneracies will be reduced (polarisation)Ex: discrimination between adiabatic and isocurvature perturbations

PLANCK


Dark Energy Equation of State

Dark energy, responsable of the acceleration of the expansion of the Universe, has an equation of state: p = w r

For a pure cosmological constant: w = -1

Planck will contribute to the measurement of w together with other probes (SNIa, Large Scale Structure, Baryonic Acoustic Oscillation, weak lensing, …),


Reionisation of the Universe• After a period where the Universe was neutral, a phase

of reionisation occured when the first objects (stars?) have been created

• Signature at large angular scales: pic dans le spectre EE (WMAP)WMAP+ACBAR+LSS Optical depth t = 0,091+-0.008

• Planck will be able to discrimate between different models of the first object formation


WMAP/Planck capacity measurement of ns

ns = 1 for the red solid line


WMAP/Planck capacity measurement of ns

ns = 0.95 and no running for the red solid line


Constraints on tensor modes with Planck

B polarization measurements at low l will put constraints on r

r=0.05 could be detected by Planck and upper limit r<0.03 (95% CL) could be set

simulation with r=0.1 and t=0,17

Efstathiou, Gratton astroph:0903.0345(Planck 24 month survey)

simulation with r=0.1 and t=0,17


Non-gaussianity properties of the anisotropies

• Inflation models predict nearly perfect model dependant Gaussian fluctuations

• Detection of non-gaussianity will be crucial to discriminate between these models

• Methods: kurtosis, skewness, 3 point statistics, test of isotropy …

WMAP data

Very cold region

Secondary anisotropies: gravitational lensing of the CMB

During their trip, CMB photons are gravitationaly slightly deviated by structures of the Universe

• Coherent deviation of the polarisation at large scale: B mode polarisation at small scale (leak from E mode to B mode) Non-gaussian signatures should be detected by Planck

• Neutrino mass affects structure formation Upper limit on mn: 0.15 eV



And a lot of other studies will be performed by astrophysicists …

Clusters of galaxies: 30 000 clusters will be detected by Planck using Sunyaev-Zel’dovitch effect (interaction of CMB photons with hot electron gaz in the core of the galaxy clusters)

Extragalactic sources (first survey since FIRAS 1992 with l>100mm)

Study of the Milky Way: dust, free-free,synchrotron radiation magnetic field

what can we learn from cmb in the planck area? (planck is going to be launch may 6)

Documents

primordial universe

universe p

cmb lhc conference isfahan6

mpcthermal history

thermalizationthermal

gevm3thermal history

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modes e