CMB anisotropy: Inflation - iucaa
CMB anisotropy: Inflation - iucaa
CMB anisotropy: Inflation - iucaa
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<strong>CMB</strong> <strong>anisotropy</strong>:a probe of primordial perturbations from<strong>Inflation</strong>Lec. VILecture courseVSP-2006 @IUCAAJune 2-9, 2006Tarun SouradeepIUCAA, Pune(tarun@<strong>iucaa</strong>.ernet.in)
•Low multipole :Sachs-Wolfe plateau• Moderate multipole :Acoustic “Doppler” peaks• High multipole :Damping tail<strong>CMB</strong> physics is verywell understood !!!Fig. W. Hu
Thompson scattering of the<strong>CMB</strong> <strong>anisotropy</strong> quadrupole atthe surface of last scatteringgenerates a linear polarizationpattern in the <strong>CMB</strong>.Three additional Power spectra : thetwo polarization modes and the crosscorrelation with temperature<strong>anisotropy</strong>.(Fig:Hu & White , 97)Initial metric perturbation mix correspondence :• Scalar perturbations predominantly generate the Electric (E) polarization mode.• Vector perturbations predominantly generate the magnetic (B) polarization mode .• Tensor perturbations generate the both modes in comparable amounts .• Temperature <strong>anisotropy</strong> Cross-correlation only with the E-mode.
E modes(Gradient)B modes(Curl)
Adiabatic ICTE, EE peak outof phase(astro-ph/0507503)
NASA/WMAP science team
<strong>CMB</strong> Task force report 2005Null BB: Awaiting direct signature oftensor perturbations, a.k.a. gravity waves !!!
<strong>CMB</strong> Task force report 2005
Near future : High resolution C l(SPT)<strong>CMB</strong> Task force report 2005
Near future : SZ Cluster surveys (SPT,ACT)<strong>CMB</strong> Task force report 2005Number count of clusters vs. redshift (dN/dz)
European space agency(ESA)Scheduled Launch in 2007
NASA’s Beyond Einstein Programnow 2014
Cosmic Gravity wave background from inflation<strong>CMB</strong> Task force report 2005
Is the Universe Compact ?Simple Torus(Euclidean)Quantum creationHomogenous & isotropicButof a Multiply connected (compact) universe ?finite universe !?!Compacthyperbolic spacePoincaredodecahedronRecent Nature article
Is the universe infinite?Torus space:space: A flat squarewhose opposite sides areconnected.
WRAPPED AROUND: signature oftopologyAll the lightreceived from aspecific timerepresents a sphere.If this sphere is larger than theuniverse, it will intersect itself
Correlated Circles(Cornish, Spergel, Starkman et al, 1998,2004)(Figure: Bond, Pogosyan & Souradeep 1998, 2002)
Temperature along the correlated circles(Figure: Bond, Pogosyan & Souradeep 1998, 2002)
BiPS signature of a “soccer ball” universe(Hajian, Pogosyan, TS, Contaldi, Bond : in progress.)Ω tot=1.013κ Ideal, noise freemaps predictions
Measured BiPS for a “soccer ball” universe(Hajian, Pogosyan, TS, Contaldi, Bond : in progress.)2.52.0Ω tot=1.013κ 1.51.01000 simulated full skymaps with WMAP noise0.5
Hunting Correlation patternsin the<strong>CMB</strong> AnisotropyAmir Hajian, Soumen Basak, Tuhin Ghosh,Himan Mukhopadhayay,…
Mildly anisotropic/rotating universe ?WMAP first year dataRotating anisotropicUniverse TemplateDifference mapJaffe et al. 2005
SphericalharmonicsalmSpherical HarmonicTransformsC lAngular powerspectrumBipolar sphericalharmonicsMA ll'BipoSHTransformsκBiPS(Bipolar Power Spectrum)Bipolar Power spectrum (BiPS(BiPS) ) :A Generic Measure of Statistical Anisotropy
Statistical Isotropy of <strong>CMB</strong> AnisotropyWMAP <strong>CMB</strong> <strong>anisotropy</strong> mapFig: NASA/WMAPscience teamHajian & Souradeep ApJ. Lett 2003Hajian, Souradeep & Cornish ApJ. Lett. 2005WMAP Angular power spectrumFig: NASA/WMAPscience teamW(l)WMAP Bipolar power spectrum (BiPS)
Used Simulated 30 GHz maps from Planck sky ModelBiPS of Polarization maps(Basak ,Hajian, TS: astro-ph/0603406)Ka
oIntriguing: Lack of power at large angular scales ( θ ≥ 60 )?NASA/WMAP science teamLow Quadrupole ΔT2= 8 ± 2μK(COBE ΔT1072=+−4μK)=2
Deconvolving the primordial power spectrum(Shafieloo & Souradeep, 2004 PRD )Cited in WMAP-3 paperPrimordial power spectrumfrom Early universe candeconvolved from <strong>CMB</strong><strong>anisotropy</strong>spectrumHorizon scaleCl=∫dkkP( k)G ( k)lImproved Error sensitiveiterative Richardson-Lucydeconvolution methodRecovered spectrum shows an infra-red cut-off on Horizon scale !!!Is it cosmic topology ? Signature of pre-inflationary phase ? QG physics ? ….
Thank you !!!
Web references for further exploration:• Basic cosmology – Ned Wright’s cosmology tutorial• Basics of <strong>CMB</strong> – <strong>CMB</strong> intro. at Wayne Hu’s homepages• Links to <strong>CMB</strong> activities worldwide - <strong>CMB</strong> resource page• MAP satellite : MAP-NASA• <strong>CMB</strong> results compilation : Max Tegmark’s webpage• <strong>CMB</strong> data analysis - Max Tegmark• Computing challenges in <strong>CMB</strong> : Bond et al.• <strong>CMB</strong> in IUCAA : Tarun Souradeep(tarun@<strong>iucaa</strong>.ernet.in)
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