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WMAP: Recent Results and Dark Energy L. Page, STScI, May 2008.

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Presentation on theme: "WMAP: Recent Results and Dark Energy L. Page, STScI, May 2008."— Presentation transcript:

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2 WMAP: Recent Results and Dark Energy L. Page, STScI, May 2008

3 A 6 parameter model agrees with virtually all cosmological measurements regardless of redshift or method. The model assumes a flat geometry, a new form of matter, something that mimics a cosmological constant, and a deviation from scale invariance ( =1, ~2.5-3  ).

4 WMAP5 only Models based on some kind of field theory of the early universe predict n s. WMAP5 + SN& BAO

5 What does the CMB ALONE tell us about Dark Energy? NOTHING! (one more bit of information is needed)

6 “Geometric Degeneracy” CMB alone tells us we are on the “geometric degeneracy” line Reduced closed open Assume flatness WMAP5 only best fit LCDM { WMAP3 WMAP5 = 1.045 Lewis & Bridle ’02

7 What’s new for WMAP5? Calibration uncertainty now 0.2% (Hinshaw et al. 2008) Full reanalysis of the main beam profiles, near lobes, and sidelobes (Hill et al. 2008). 1% shift in solid angle, uncertainties halved. Developed new foreground cleaning methods for temperature (Gold et al. 2008) and polarization (Dunkley et al. 2008). However, basic results use original methods. Nominal sky mask updated to “KQ85” (keeps 85%) vs Kp2 (keeps 97%) plus ~750 sources. (Gold et al., Wright et al. 2008) Selected highlights:

8 Why care about the beam profiles? Three different spectra that differ only in spectral index. The black line is the best WMAP model.

9 Spectral Index Normalize the spectra to l=220 (mimics n s - amplitude degeneracy) The two window functions are for 0.1 deg FWHM beams with a 1% difference in solid angle. Only WMAP has achieved anything like this accuracy.

10 Spectral Index Divide by fractional window function. Conclusion: To probe the index the beams need to be understood to the 1% level. In addition, there are astrophysical challenges.

11 Full beam reanalysis led to: Consistent with earlier error bars but systematically higher. Hill et al. 2008

12 The Data 23 GHz 33 GHz 41 GHz 61 GHz 94 GHz WMAP5- WMAP3 Hinshaw et al. 2008 125 mK 67 mK 48 mK 24 mK 17 mK

13 WMAP5 TT&TE Spectra 3 yr Nolta et al, Hinshaw et al. 2008 Particle horizon at decoupling ACBAR and CBI go to l=3000

14 New Polarization Maps Hinshaw et al. 2008

15 EE Power Spectrum Nolta et al. 2008 After accounting for foreground emission, the BB, EB, TB spectra are all consistent with zero. Uncertainties include cosmic variance. l by l

16 Optical Depth, The square of the optical depth is essentially the average of the low l EE data. Of course, the quoted values come from the full analysis. Hinshaw et al. 2008

17 Analysis of curvature (and thus the presence of w=-1 Dark Energy) With the HST prior, h=0.72 +/- 0.08, -0.052< <0.013 (95%cl) k

18 By adding BAO and SNIa, we find: -0.0181 < Ω k < 0.0071 (95% CL) Can convert to limits on the curvature radius of the universe: For negatively curved space (Ω k >1): R>23/h Gpc For positively curved space (Ω k 36/h Gpc Komatsu et al 2008 Now add BAO and supernovae

19 For combined data, w= -0.97 +- 0.06 Komatsu et al 2008 Now relax flatness and w=-1 assumptions Need both SN and BAO to limit the curvature and the dark energy equation of state

20 No significant running index is observed. WMAP-only: dn s /dlnk = -0.037 +/- 0.028 WMAP+BAO+SN: dn s /dlnk = -0.032 +/- 0.020 Early Universe: WMAP consistent with power law (Note that 1 parameter is added) Dunkley et al 2008 Komatsu et al 2008

21 Use WMAP to constrain tensor-to-scalar ratio: tensors produce B-mode polarization, but also a large-scale temperature signal. (Currently low-l BB limits r < 20) Early Universe: Limits on Gravitational Waves Dunkley et al 2008 With all data: r < 0.20 (95% CL) Komatsu et al 2008

22 NASA/GSFC Bob Hill Gary Hinshaw Al Kogut Michele Limon Nils Odegard Janet Weiland Ed Wollack Princeton Norm Jarosik Lyman Page David Spergel UBC Mark Halpern Chicago Stephan Meyer Hiranya Peiris Brown Greg Tucker UCLA Ned Wright Science Team: WMAP A partnership between NASA/GSFC and Princeton Johns Hopkins Chuck Bennett (PI) Ben Gold David Larson Cornell Rachel Bean Microsoft Chris Barnes CITA Olivier Dore Mike Nolta UAB Licia Verde UT Austin Eiichiro Komatsu Oxford Jo Dunkley

23 THANK YOU

24 Non-Gaussianity The quadrupole is not anomalously low. For the full sky, the 2-pt correlation function is not anomalous. Most “detections” of non-Gaussianity are based on a posteriori statistics. That is, one seeks any oddity in the maps and quantifies it. The North-South asymmetry was visible in the COBE data. It would be wonderful to find a clear signature of cosmic non-Gaussianity. The WMAP team has not found one yet.

25 Non-Gaussianity Look for non-Gaussianity by looking for non-zero bispectrum = 3 point function Define ‘f NL ’ using curvature fluctuations: Φ (x)= Φ gauss (x)+f NL [ Φ gauss (x)] 2 -9 < f NL (local) < 111 (95% cl) (Komatsu et al 2008) -151 < f NL (equilateral) < 253 (95% cl) (Komatsu et al 2008)

26 A significant fraction of the full-sky quadrupole comes from: Extra cold spot: ( Vielva et al. 2004, Cruz et al. gave 1.8% prob. 2005) (Hajian 2007) Note “fingers” present in the southern Galactic hemisphere. Largest effect in almost ecliptic coord. Detection of SH persists! Alignment? (de Oliveira-Costs et al. 2004)

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