1. Cosmology from Large Scale Structure Surveys
Changbom Park Feb. 27, School of Physics Korea Institute for Advanced Study

2. A sketch of
Astronomer's methods to measure cosmological parameters (DE's w)

3. 『What we want to know』 1. Spacetime 2. Matter 3. Phenomena/Laws
Homogeneous & isotropic space
Geometry & topology of space (flat & infinite?)
Expansion of space ( matter)
Past and future of the Universe (why now?)
2. Matter
Contents and nature (what & how much)
Primordial fluctuation ()
Structure formation (when & how, environment)
3. Phenomena/Laws

4. the Uni-verse: a map of our play-ground

5. 1. Recombination & Decoupling
Dark First NL Evolution LSS hear & now
age structures of galaxies
1. Recombination & Decoupling
 CMB radiation. Let there be primeval light !
2. Dark Age
 What is buried here?
2. First structures & Reionization
 Let there be star light !
4. High-z objects and Evolution of galaxies
 Quasars, Ly-a forest clouds
5. Large-scale structure and nearby objects
 Cosmic zoo: clusters, voids, filaments & walls of galaxies
Recent events in the universe

6. Expansion of space & Growth of structures
Ideas to draw information on the universe
1. Look at primordial fluctuations directly
CMB (+neutrino, gravitational wave)
=> geometry of space, matter contents, matter P(k), non-Gaussianity
3. Study the expansion history of the space : H(t) or r(z)
use standard candle (SN Ia), rulers (BAO, topology)
=> matter contents (DE w)
4. Measure the growth of structures
use gravitational lensing, cluster abundance
depends on expansion of space, matter power spectrum
5. Study the properties of non-linear structures
properties of galaxies, clusters
Expansion of space & Growth of structures

7. Cosmic microwave background anisotropy:
CMB anisotropy: Primordial & ISW
Cosmic microwave background anisotropy:
geometry of space, matter contents, matter P(k), non-Gaussianity
only at z~1100, 2d map, foregrounds

8. WMAP Experiment WMAP Observatory
Launched on 30 June 2001 to L2 of Sun-Earth system
1.4m*1.6m primary + 10 feed horns in each 2 focal plane
Bands
1 K
1 Ka
2 Q
2 V
4 W
Ν [GHz]
22.8 33
40.7
60.8
93.5
FWHM [°]
0.82
0.62
0.49
0.33
0.21

9. Observed ΔT Maps W 94GHz 0.21° V 61GHz 0.33° Q 41GHz 0.49°
K 23GHz 0.82°
Ka 33GHz 0.62°
Galactic emission
+ CMBR
+ others

10. WMAP's 3 year Map
Park, Park, Gott (2007)

11. Spergel et al. (2007)
3yr & 1yr data
3yr & 1yr fits

12. Shape of T Power Spectrum
Super-horizon scale fluc.
SW effect
1∼0.1rH fluc. with initially coherent phases
Oscillation & Doppler effect
Radial averaging & radiation diffusion

13. Spergel et al. (2007)
3yr & 1yr constraints

14. Park, Park, Gott (2007)

15. HI HI HI HI HI HI HI HI HI HI HI HI HI HI HI HI
3D HI distribution & reionization

16. 3D HI distribution : 21cm tomography mapping most of our observable universe
Power spectrum of 21cm fluctuations HI HI HI HI HI HI HI HI HI HI HI HI HI HI
Bright in HI !

17. Gravitational Lensing: Strong & Weak
only projected mass along the line of sight

18. Shear map expected in SCDM
Jain, Seljak & White (2000)
mass fluctuations along the line of sight >Weak lensing by LSS > coherent distortions in the observed shapes of background galaxies
Shear map expected in SCDM

19. CFTHLS weak-lensing survey: i<24.5 & 22 deg2
Spergel (2007)

20. Type Ia Super Novae
Intrinsic dispersion, systematics

21. r(z) relation : Expansion history
SN Ia as a standard candle
Transition from deceleration to acceleration at z= 0.46 ± 0.13
(Riess et al. 2004)

22. μ = m-M = 5log dl + 25
Ωm=0.27, ΩΛ=0.73
Riess et al. (2007)

23. Matter contents Dark energy Ωm=0.29±0.050.03, ΩΛ=0.71 (if flat U)
(Riess et al. 2004)
(Riess et al. 1998)
(Riess et al. 2004)
Matter contents
Ωm=0.29± , ΩΛ=0.71 (if flat U)
Dark energy
w = -1.02± , w<-0.76 at 95% (if P=wρc2)

24. Clusters

25. Clusters of galaxies Searched by X-ray, SZ effect abundance d2N/dMdz
spatial distribution P(k)

26. Future experiments
clusters
CMB
SN Ia

27. Large Scale Structure in linear ~ quasi-linear regime : P(k), BAO, Topology

28. Geometric methods using the large scale structures
Standard rulers (Actual objects or Features in PS/CF)
 measure Δz & Δθ  H(z)DA(z)  Ωm, ΩΛ, w
(=dt/a)
r|| r┴
(=r dθ)
where
H(z)

29. BAO (ex) Features in PS & CF Baryonic oscillation in PS
Baryonic bump in CF
of deep redshift sample
 Ωm, ΩΛ, w
We know actual length!
Acoustic oscillation : amplitude depends on Ωb
scale = comoving sound horizon ‘s’ at last scattering
kA = 2π/s depends strongly on Ωm, weakly on Ωb not on DE
 Curvature of space, Baryonic mass

30. SDSS DR5 Best fit m=0.26 (Percival et al. 2007)
Main galaxies and LRGs
BAO+HST h=0.72
BAO+WMAP3
Best fit m=0.26

31. Power Spectrum from CMB & LSS : Ωm
But biasing relative to matter

32. Linear scale structures do not change shape
(Springel)
Linear scale structures do not change shape
Intrinsic topology of LSS insensitive to biasing & redshift distortion

33. LSS topology as a standard ruler
Primordial density
Dark matter at z=0
LSS topology as a standard ruler
Dark halos at z=0 in r
Dark halos at z=0 in z
25h-1Mpc Gaussian smoothing

34. Cosmological parameter estimation from LSS topology
curvature in P(k) => genus(λ) depends on cosmology
Inconsistency test !
given z => choose a cosmology, i.e. r(z) => measure genus(λ) => compare model prediction & measurement of genus

35. Constraint on Ωm better than WMAP3

36. Properties of non-linear structures

37. ? LSS CMBR 70s BB+(γ,ν; baryon)+GI Dark matter 82Inflation
80s CMBR dT/T < 10-4
Late70s Discovery of LSS
mid80 SCDM Model BB+Inflation+(γ,ν; baryon, CDM)+GI
92 COBE dT/T~10-5
92 LSS P(k)
SCDM Model ruled out
98 Accelerating expansion
WMAP Cℓ
>2000 Concordance LCDM Model BB+Inflation+(γ,ν; baryon, CDM; Dark E)+GI
SDSS JWST
many more
Planck ?
Topology of space; matter contents; matter fluctuation & structure formation

40. Small scale 1/√N reduction
Decoupling surface
Acoustic oscillation
Small scale 1/√N reduction
& Photon diffusion
Width Δz=195 Δr=44Mpc
1. Inflation  Same initial phase of oscillation  peaks & troughs in PS
2. Baryonic λJb 2200Mpc ≫ Horizon rHdec 320Mpc > Sound horizon λs 270Mpc
> Width Δr 44Mpc > Photon Diffusion λD 14Mpc

41. 3. Gaussianity of ΔT/T Minkowski functionals
G(ν)=(Nhot-Ncold)/2πA
 Gaussian: No frequency, scale dependence !
Non-Gaussianity Detected! (Park & Park 03)