1 / 39

The Importance of Non-Gaussianity in Cosmology: Insights from the CMB Studies

This article discusses the critical role of non-Gaussianity in the development of cosmology, particularly concerning cosmic microwave background (CMB) observations. It covers the transition from primordial Gaussian fluctuations to non-linear structures such as galaxies and clusters, the significance of statistical properties of adiabatic perturbations, and methods of detecting non-Gaussian signals. By referencing precision cosmology and data from missions such as WMAP and PLANCK, the paper aims to unravel the complexities of the universe's evolution, dark matter, and dark energy.

lada
Télécharger la présentation

The Importance of Non-Gaussianity in Cosmology: Insights from the CMB Studies

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Collaborators within DK-Planckcommunity Lung-Yih Chiang (NBI) Andrei Doroshkevich (TAC,ASC FIRAN) Per Rex Christensen (NBI) Igor D. Novikov ( NBI) H..U Norgaard -Nielsen, DSRC Oleg V. Verhodanov (TAC,SAO RAN) Pavel D. Naselsky ( NBI)

  2. Why the issue of Non-Gaussianity is important for development of cosmology ? Non-Gaussianity of the CMB sky P.Naselsky NBI, the PLANCK scientist

  3. “BIG BANG” Ω≈1 n≈0.97 Gaussianity!! P(δ)dδ~exp(-δ ²/2σ²)dδ Non-linear development of the quantum fluctuation Non-Gaussianity!!

  4. Transition from primordial (Gaussian) fluctuations to non-linear structures (galaxies , clusters and LSS ) change statistical properties of the adiabatic perturbations.

  5. Picture of the Quantum fluctuations from Inflation in radio waves

  6. Definition of the power spectra Gaussian or non-Gaussian Gaussian only !

  7. Cosmology before WMAP

  8. The temperature anisotropy and temperature polarization cross power spectrum Precision cosmology !!!

  9. WMAP +……. SN1a,2dF,He, D BOOMERANG, MAXIMA-1,CBI,ARCHEOPS,VSA,DASI, BIMA +……. SN1a,2dF,He,D… CMB Ω h =0.02 ! 2 b WHY NOT FOR US ? Cosmologyof the XX century

  10. Cosmologyof the XXI century Important question is WHY? 1/π ? (D=3)/(D=10) ? Dark matter density Dark energy density ≈1/3 Extradimensions ? Topology ? ? What about Baryosynthesis? Baryonic matter density Dark matter density

  11. Dark energy } Development of Cosmology and High energy physics Dark matter Φ(x, t)=Ψ(x, t)* exp [iΛ(x, t)] Baryonic matter S.Bonometto et al,2004,2005

  12. Non linear theory of dark energy-dark matter coupling • Link between adiabatic and isocurvature perturbations • Weak Non-Gaussianity of the CMB Reionization of the cosmic plasma by the first quasars, galaxies, and stars

  13. Reionization 300 Mpc 3Mpc

  14. WMAP ? PLANCK, 2007

  15. Two news from the WMAP data analysis • The CMB signal is • Gaussian ! Komatsu et al, 2003 (WMAP team ) 2. The CMB signal is non- Gaussian

  16. WMAP map: Gaussian by WMAP science team with 95% CL ! ? |f |<100 Df = DF + f *DF*DF

  17. Non-Gaussianity is not a dog!” Ya.B.Zel’dovich , f*ΔΦΔΦ

  18. The definition of Gaussianity

  19. Methods of detection of Non-Gaussianity in the WMAP sky Image domain Multipoles domain 1.Peak statistics 2. Minkowski functionals 3. Wavelets 4.Curvature distribution 5.Non-uniformity of the power spectra distribution over patches of the sky 6.Skiwness and kurtosis 7. Bispectrum ……………. 1.Phases analysis (trigonometric moments of phases, phase cross-correlations, Pearson’s random walk statistic, 2.Minkowski vectors 3. Cooper's statistic for phases WMAP signal is Non-Gaussian

  20. FOREGROUNS + instrumental noise+ systematic effects

  21. CMB maps derived from the WMAP data NOT FOR INVESTIGA- TION OF THE CMB !!!?? FCM l<512 ILC l<100 WFM l<512 ErFM l<512

  22. Image analysis for non-Gaussianity test Pixel by pixel

  23. Foregrounds ? ILC-ErFCM FCM-ErFCM V band l=400 ILC-WFM

  24. WMAP KP masks

  25. Asymmetry of the CMB power

  26. *South-north asymmetry of the COBE and the WMAP signals. NEP SEP Global anisotropy of the Universe. NEP WHY ? SEP

  27. Non-CMB tools Q-W FCM WFCM V-W FCM-WFCM MV

  28. NON-CMB L<100 L<512 L<30

  29. Alignment of the low multipoles Schwarz et al,2004 ?

  30. Gaussian Random Fields Strict definition of Gaussianity: They possess Fourier modes whose real and imaginary parts are independently distributed and both Gaussian, Weak definition of Gaussianity : random phase hypothesis the Fourier phases are uniformly random between 0 and 2p (by Central Limit Theorem)

  31. transformed Planck Planck satellite and transformed Planck have the same power spectrum (same|dk|), they have different “faces” due to different phases: It is phase Fk that keep Max’s face, not amplitude |dk| !! Planck satellite Max Planck |dk| exp(iFk) |dk| exp(iFk) |dk| exp(iFk) FT-1[ ]

  32. Asymmetry of the WMAP phases

  33. Foreground-cleaned map m Foreground-cleaned map ℓ

  34. Asymmetry of the WMAP phases ILC TOH WTOH L-1,L+1 correlation through m- direction M-1,M correlation through - L direction NO Evidence of Primordial Magnetic Field ! Naselsky, Verkhodanov, Novikov,Olesen,Chiang,ApJ,2004

  35. Non-Gaussianity of the WMAP. WHY ?

  36. NON-GAUSSIANITY Primordial (Inflation ?) Foregrounds + systematic Df= DF + f *DF*DF NEW PHYSICS S= G + NG

  37. Summary 2003-2005 1.Residues of the foregrounds separation Chiang ,Naselsky, Verkhodanov and Way,ApJ.Lett2003; Naselsky , Doroshkevich and Verkhodanov,ApJ.Lett,2003; Naselsky , Doroshkevich and Verkhodanov,MNRAS,2004; Park, MNRAS,2004; Eriksen, D.Novikov, Lille,Gorski, ApJ,2004 ; Naselsky, Verkhodanov, Novikov,Olesen,Chiang,ApJ,2004,… 2. Systematic effects Hansen, Vittorio,ApJ.Lett.2004 (+) Vielva et al,MNRAS, 2004 (-) 3. Primordial Bershadskii, Skrinevasan, Phys.Lett.,2003;2004 (magnetic field) Vielva et al,MNRAS, 2004 Hansen, Bandy, Gorski,MNRAS,2004 Wandelt ,ApJ.Lett,2004

  38. Non-Gaussianity is not a dog!” Ya.B.Zel’dovich Sorry!

More Related