THE PRIMORDIAL FIREBALL. Joe Silk (IAP, CEA, JHU)

Transcription

1 THE PRIMORDIAL FIREBALL Joe Silk (IAP, CEA, JHU)

2 CONTENTS OF THE UNIVERSE

3 Albert Einstein Georges Lemaitre Alexander Friedmann

4 George Gamow Fred Hoyle

5 1930 Albert Einstein Edwin Hubble

6 velocity 1929: Hubble obtained slope H=530 km/sec/mpc Alexander Friedmann: 1924 prediction of expansion 1927: Georges Lemaitre independently predicted expansion, obtained H=625 km/sec/mpc but published in French distance

7 Willem de Sitter

8 Log(distance) 80 years progress redshift Betoule

9 1949 nuclear physicists plunge in

10 predicted origin of light elements & fossil radiation in 1949 helium deuterium RALPH ALPHER, GEORGE GAMOW, ROBERT HERMAN lithium

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12 957 Geoffrey Burbidge Margaret Burbidge William Fowler Fred Hoyle

13 ARNO PENZIAS AND ROBERT WILSON 1964 RELIC RADIATION DISCOVERED

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15 A SPACE-TIME DIAGRAM OF THE UNIVERSE THE DARK AGES ON ANGULAR SCALES ABOVE A DEGREE, WE ARE VIEWING QUANTUM FLUCTUATIONS IN THE SKY!

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17 FROM PRIMORDIAL FLUCTUATIONS TO GALAXY FORMATION Planck 2014 BICEP

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19 A VIEW OF THE EARTH AT COBE RESOLUTION

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21 WMAP satellite Wilkinson Microowave Anisotropy Probe 9 years of data (2010) Charles Bennett David Wilkinson

22 Jean-Loup Puget 2013 Planck satellite Reno Mandelesi

23 PRIMORDIAL SOUND WAVES IN THE PHOTON-BARYON PLASMA BECOME DENSITY FLUCTUATIONS IN DARK MATTER-DOMINATED ERA fluctuation strength WEAKLY INTERACTING DARK MATTER BOOSTS FLUCTUATION GROWTH time

24 FROM DENSITY FLUCTUATIONS TO GALAXIES Temperature fluctuations measured by Planck satellite compared to inflation prediction Fourier transform of temperature anisotropies Fluctuations propagate as sound waves until transparency Peaks are sound wave maxima/mimima at last scattering of photons Photon mean free path increases as density decreases until fluctuations are damped

25 Angels and demons The implications of a curved space as seen by M.C Esher hyperbolic geometry spherical geometry

26 EUCLIDEAN or flat space FITS HTO 0 =68+-1 HIGH km PRECISION! s -1 Mpc -1 W= 8pGr/3H 0 2 WMAP7 curved flat W L = W m = W B = The geometry of the universe is Euclidean! t 0 = Gyr

27 The next challenge: POLARIZATION 2015 Twisting of the CMB by gravity waves from the epoch of inflation at sec Dust and gravitational lensing are foregrounds to be removed The holy grail!

28 T/S< GRAVITATIONAL WAVES ARE THE UNIQUE IMPRINT ON CMB OF THE BIG BANG AT SEC. HAVE THEY HAVE BEEN DETECTED? From a few milli-kelvin relative to 2.7K at yrs BICEP2 at the South Pole to a few 10s of nanok

29 Planck at 30 GHz: dust is everywhere

30 Sub-orbital by 2017 Advanced ACTpol, SPT-3G SPIDER Limit T/S~0.01 Polar Bear, Simons Array, BICEP3/KECK array, CLASS. Space by 2022 LITEBIRD JAXA/NASA phase A /30 ESA M5? Limit T/S~0.001 low l cosmology is cosmic variance and theory limited 30

31 FUNDAMENTAL PHYSICS CHALLENGES FOR A FUTURE SPACE CMB EXPERIMENT Damping tail and m n Primordial B modes Beyond the standard LCDM model Recombination epoch?? What is the choice for a future space mission? To B or not to B? the polarization by primordial gravity waves Is divergence free, only stretching, like a magnetic field 31

32 1. Thermalization (g,e-) by double Compton scattering occurs at z > z m =2x10 6 (0.0224/W B h 2 ) 2/5 create photons before 1 yr e - +g --- e+g+g (also bremsstrahlung: e - +X --- e - + X + g ) t m = (W B h 2 /0.0224) -1 ( /z) 9/2 s 2. conserve photons Equilibration (g,e - ) to Bose-Einstein by Compton scattering occurs at z m < z < z y = 2.15x10 4 (1/W B h 2 ) 1/2 results in m distortion (e - +g --- e+g) before 10 4 yr 3. Heating of photons z < z y : Compton scattering produces y distortion 4. Recombination at z LSS = Reionization at z~ 9 32

33 m distortion Spectral distortions are the next frontier > 3 order of magnitude improvement is feasible! 33

34 y m+y hybrid m Search for 3 numbers 34

35 A search for spectral distortions Guaranteed signal Density fluctuation damping gives m=10-8 complements CMB acoustic peaks Pajer & Zaldarriaga 2013 clusters dwarfs CDM subhalos These numbers are integrated over z the most massive galaxy clusters The first star-forming dwarfs Can we do better? 35

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37 DI n [J m -2 s -1 Hz -1 sr -1 ] Cosmological recombination spectrum Effect of free-free absorption HI spectrum HeI spectrum Changes in line shape and position due to He HeII spectrum Total distortion Total distortion /w feedback Transitions among highly excited states Brackett a Paschen a Balmer a Lyman a high-n distortion reprocessed Challenging as ~10 8 CMB photons/baryon means spectral distortion ~ Chluba & Ali-Haimoud 2015 n [GHz] 37

38 t= m =10-7 y= What i PIXIE NASA prop 16 sq deg patches, 0.5 arcmin beam Desjacques, Chluba, JS, de Bernardis, Dore 2015 MILLIMET Russian 12 m telesco MILLIMETRON: a cooled 12m telescope 38 + spectrometer with <10 GHz resolution

39 FUTURE SPACE MISSIONS WITH SPECTRAL CAPABILITY PIXIE for 2022 launch? T/S ~ (1s) + possibility of finding m at z~10 6 and y at z~10 3 cf: LiteBIRD s design goal is ~few x 10-4 for 2022 launch THE PROMISED LAND PIXIE+ With modest increase (x 3) in sensitivity, a significant detection of m is guaranteed HYPERPIXIE: Theorist s dream: Revelatory for recombination at z = 1080 & for primordial He BUT need 30x PIXIE sensitivity! a billion $ mission Chluba PIXIE