Detection of integrated Sachs-Wolfe effect by cross-correlation of the cosmic microwave background and radio galaxies. 中央研究院. Guo Chin Liu. Collaborators: Ue-Li Pen (CITA) K-W Ng(IoP, AS). [email protected] Hubble Diagram with 42 High-Redshift Supernovae.
Something is missing for the “cosmological principle” based Friedmann universe.
Evolution of SN Ia is small.
D. Branch et al. 2001
Perlmutter et al. 1998
CMB contains richest information of our universe.
Age of universe
Content of universe
Geometry of universe
Thermal history (reionization)
Geometry of our universe
Spergal et al. 2007
Astronomical Observation for Dark Energy the existence of dark energy.
Current used observations
Other possibilities the existence of dark energy.
Dark energy couples with cold dark matter : Changing matter power spectrum
S. Lee, G. Liu & K. Ng PRD 2006
Coupling with CMB photons: Producing parity odd term in CMB polarization power spectra
G. Liu, S. Lee & K. Ng PRL 2006
The physical quantity to be determined: the existence of dark energy.
Equation of state w(z)=p/
Cosmological constant: w=-1
Quintessence : wQ: w0, w0+(1-a)w1, oscillating….
a. Assume flat universe and const. w
w=-1.05+0.15-0.2 Knop et al.2004 (SN)
b. time evolution w=w0+ (1-a)w1 w0=-1.146+0.176-0.178
w1=0.6+0.622-0.652 --no dark energy perturbation
w1=0.499+0.453-0.498 -- with dark energy perturbationG-B Zhao et al. 2006(SN+CMB+galaxy clustering)
CDM explains observation data very well
Inhomogeneity the existence of dark energy.
Cosmologists are often in error, but never in doubt the existence of dark energy.Lev Landau
Fu the existence of dark energy.ture observation
Weak lensing:Size of distortion image depends on distance traveled and growth factor
BAO: Baryon Acoustic Oscillation is sensitive to dark energy through its effect on the angular-diameter distance vs. redshiftrelation and through its effect on the time evolution of the expansion rate.
Clusters observation: growth rate and geometry of universe
the existence of dark energy.2
Second Hint from CMB
T/T=-2 d d/d
Try to look forcorrelation of CMB with matter
Density fluctuation the existence of dark energy.
CMB gains energy
Cross correlation of CMB with matter in local universeProposed by Crittenden & Turok (1996)
Contribution to Signal from different Redshift the existence of dark energy.
Crittenden & Turok PRL 1996
First detection of the cross-correlation the existence of dark energy.
Correlating CMB sky to hard X-rays (HEAO-1) and radio galaxy (NVSS)
3 sigma detection for hard X-rays and 2.5 sigma for radio galaxy
Boughn & Crittenden, nature, 2004
Contamination the existence of dark energy.
Details of this work I the existence of dark energy.
NVSS data the existence of dark energy.
1. 1.4GHz , 82% sky coverage (>-40)
2. Sensitivity 2.5 mJy contains 1.8 million sources
3. Typical luminosity function models indicate 0z2 distribution
Detail II the existence of dark energy.
Result I the existence of dark energy.
CMB anisotropies & polarization on large scales the existence of dark energy.
CMB last scattering surface
Generate P. for l>100
Generate P for l < 30~50
Dark energy dominates
Correction by the information of polarization the existence of dark energy.
At large scales T=TSW + Tre+ TISW
E(no ISW) =aT(no ISW) + n
<TE> = a <TT>
<EE>=a2<TT> + n2
T(ISW) =T – E/a * WF
Result II the existence of dark energy.
Discussion & Summary the existence of dark energy.