Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Masashi hazumi talk

205 views

Published on

ECL_MH_16

Published in: Science
  • Be the first to comment

  • Be the first to like this

Masashi hazumi talk

  1. 1. Tests of Cosmic Inflation with Measurements of Cosmic Microwave Background Polarization LiteBIRD POLARBEAR Masashi Hazumi High Energy Accelerator Research Organization (KEK) and Kavli Institute for Mathematics and Physics of the Universe, The University of Tokyo and Graduate School for Advanced Studies (SOKENDAI) and Institute of Space and Astronautical Science, JAXA 1
  2. 2. My research history 2 1994-2008: B Factory at KEK Discovery of CP violation in B decays à Kobayashi-Maskawa Nobel 2008 2007: KEK CMB Group officially established 2005: my “cosmic survey” à chose CMB ! POLARBEAR QUIET 2012 - Now 2008-2010 Telescopes in Atacama, Chile 2014: Joined Kavli IPMU as a Project Professor to promote LiteBIRD satellite project (80% KEK, 20% IPMU) LiteBIRD satellite 2024-25: Launch 2015: LiteBIRD Proposal Now-2020s: Simons Array GroundBIRD
  3. 3. 3 Prologue
  4. 4. My current research area is Experimental Particle Cosmology 4 What is it ?
  5. 5. 5 Cosmic Ouroboros http://www.cc.kyoto-su.ac.jp/department/physics/image/deptphys/hebi.png Particle Cosmology seeks answers to the big questions •  How did our universe begin ? •  What fundamental laws governed the beginning of our universe ? Deep connection to our existence Sense of wonder ! Joy of experiments •  You can invent new instruments. Great invention often changes the world ! •  You can see data that no one else has ever seen.
  6. 6. A striking fact about particle physics •  We already have “rules with no exception (!)”, as long as experiments on the ground are concerned = the Standard Model of particle physics (Quantum Physics !) 6 Many Nobel prizes awarded for the Standard Model
  7. 7. Breakdown of the Standard Model of particle physics •  Cosmological observations are incompatible with the Standard Model of particle physics 1.  Inflation (accelerating expansion of the early universe) 2.  Matter anti-matter asymmetry of the universe 3.  Dark matter 4.  Dark energy 7 Big riddles are in front of us.
  8. 8. Particle physics perspective on the beginning of our universe •  Our universe is governed by general theory of relativity (GR) invented by Albert Einstein. •  GR is a classical theory with no quantum fluctuation. •  The Big Bang however points sizable quantum fluctuations of space-time in the very early universe. 8 Breakdown of GR ! à Quantum Gravity (e.g. Superstring theory)
  9. 9. •  We have very interesting hypotheses about quantum gravity (such as superstring theory), but we do not yet know what it really is. •  Need clever measurements to observe effects of quantum gravity ! •  Cosmic Microwave Background (CMB) polarization is our best hope ! 9
  10. 10. 10 Introduction to CMB
  11. 11. 11 1929 1965 1915 1991 Spacetime curvature is determined by matter and radiation. Our universe is expanding ! Direct evidence for Hot Big Bang ! General relativity (Einstein) •  Proof of black-body radiation •  CMB anisotropy à Indication of cosmic inflation now COBE Mather Smoot Nobel (2006) Nobel (1978) Cosmic Microwave Background (CMB) Penzias Wilson Red shift of distant galaxies (Hubble) Recent meas.
  12. 12. 12
  13. 13. 13
  14. 14. 14
  15. 15. 15
  16. 16. 16
  17. 17. GPS 17 http://www.sugilab.net/jk/joho-kiki/4104/ Clocks on GPS satellites are faster than those on ground (28.6µs/day) Without any correction, GPS position error will be 11km in a day !
  18. 18. 18 http://ned.ipac.caltech.edu/level5/Sept02/Kinney/Kinney3.html
  19. 19. 19 CMB @ 50 workshop (June ’15 Princeton U.)
  20. 20. CMB temperature 20 COBE ~160GHz 2.725±0.002 K (1999) Perfect black body ! (Planck distribution) Excellent agreement with theory expectations
  21. 21. COBE 21 Tiny temperature anisotropy of 0.001% 0.001% of 3K ~ 30microK
  22. 22. What is CMB temperature anisotropy ? •  CMB is the oldest light. •  The CMB anisotropy is regarded as the “initial condition” of structure formation at later times. •  The Big Bang implies quantum fluctuations of space-time in the very early universe (earlier than CMB generation) •  Therefore, CMB temperature anisotropy implies that the origin of our existence is quantum fluctuations ! 22
  23. 23. 23 Quantum flucuation of space-time Now Scientific answer to a philosophical question ! Quantum fluctuation of space-time gives the initial condition of structure formation.
  24. 24. Major players for CMB temperture anisotropy measurements today 24 Planck SPT ACT WMAP
  25. 25. 25 Planck collaboration arXiv:1502.01582 Temperature fluctuation
  26. 26. 26
  27. 27. http://map.gsfc.nasa.gov/resources/camb_tool/ cmb_plot.swf 27
  28. 28. 28
  29. 29. Energy density of our universe 29 暗黒エネルギー(68%) 暗黒物質   (27%) 通常の物質   (5%) Dark Energy Dark Matter Matter
  30. 30. Age of our universe 30 The position of the first peak is a key piece of information. 13.8 billion years (uncertainty < 0.1 year) Planck 2015
  31. 31. Cosmology is exact science ! ΛCDM (The Standard Model of Cosmology) just 6 parameters ! 31
  32. 32. CMB Observation History 32 Now Temperature fluctuation Polarization fluctuation Discovery
  33. 33. 33 Cosmic inflation
  34. 34. Inflation hypothesis (~1981) 34  Accelerating expansion before the hot big bang Resolve outstanding problems of the naïve big bang model •  Horizon problem •  Flatness problem •  Structure formation Impossible within the Standard Model of Particle Physics ! Katsuhiko Sato Alan Guth Andrei Linde Alexei Starobinsky 2014 Kavli Prize awarded to Guth, Linde and Starobinsky for pioneering the theory of cosmic inflation
  35. 35. Enormous Accelerating Expansion of Inflation 35 In 0.0000000000000000000000000000000000001 second, 100000000000000000000000000 times !
  36. 36. What do we know about time evolution of ? 36 a The scale of our universe is expressed by just one quantity a
  37. 37. Friedmann equation •  Einstein equation gives time evolution of metric gµν from first principle. •  Imposing “Cosmological principle”: no special place in the universe 37 gµ⌫ = 0 B B @ 1 0 0 0 0 a2 (t) 0 0 0 0 a2 (t) 0 0 0 0 a2 (t) 1 C C A energy density of matter and radiation In particular, Expanding universe ! Friedmann Eq. for flat universe ⇣ ˙a a ⌘2 = 8⇡G 3 ⇢ ˙a > 0
  38. 38. Yet another Friedmann equation 38 ¨a a = 4⇡G 3 (⇢ + 3p) Pressure >0 for matter and radiation ¨a < 0With known matter and radiation, our universe should always be decelerating
  39. 39. Particle physics of inflation 39 •  New particle called “Inflaton” •  Simplest model with just one inflaton needs to be tested •  Inflation is so-to-speak “standard model Higgs” in cosmology
  40. 40. Emission of primordial gravitational waves graviton graviton 40 Quantum fluctuation of space-time Inflation pulled apart much faster than any other situation: virtual particles à real particles Cf. Scientific American January 2001 Caldwell and Kamionkowski
  41. 41. 41 image credit NASA/WMAP team
  42. 42. 42 Test of cosmic inflation with CMB polarization
  43. 43. Physics at recombination 43 HOT HOT COLD COLD Local quadratic anisotropy in photon density around electrons results in CMB polarization. This is just text-book physics.
  44. 44. E-mode and B-mode 44 Polarization map is decomposed into E-mode and B-mode. Divergence, even parity Curl, odd parity E-mode B-mode
  45. 45. Last scattering occurred in the primordial gravitational waves. 45
  46. 46. “HOT-COLD” w/ gravitational waves 46 contracted = HOT stretched = COLD
  47. 47. 47
  48. 48. 48 Simulation Test pattern on CMB Space-time fluctuation due to inflation can be detected as CMB polarization !
  49. 49. 49 credit: New Scientist hot electrons emerged again à rescattering and additional B-mode with larger angular scales Reionization
  50. 50. Lensing B-mode – ``Another” B-mode by Weak lensing 50 (image credit: ESA) E-modes B-modes at sub-deg. scale •  Better ns from E-mode •  Sum of neutrino masses •  (Early) Dark energy
  51. 51. E mode Primordial B mode (not yet detected) Reionization dozens of degrees Recombination ~2 degrees Ground-based large telescopes, neutrino masses, dark energy Satellite ! Shed light on inflation energy scale Determination of r (tensor-scalar ratio) 51 CMB polarization power spectra
  52. 52. 52 Physics of CMB B-mode •  Direct evidence for cosmic inflation •  GUT-scale physics •  Arguably the first observation of quantum fluctuation of space-time ! V 1/4 = 1.06 ⇥ 1016 ⇥ ✓ r 0.01 ◆1/4 [GeV]
  53. 53. B-mode power spectrum measurements 53Figure by Yuji Chinone Primordial Gravitational waves Lensing
  54. 54. 54 International collaboration w/ ~20 institutions and ~100 researchers
  55. 55. 55 More on instruments will be covered in my talk titled “The Cosmic Microwave Background and How to Detect It” tomorrow.
  56. 56. 56
  57. 57. Constraint on r 57 r < 0.07 at 95% C. L. Symplest inflation model is already ruled out ! Planck, WMAP, BICEP2, Keck
  58. 58. B-mode projects (1) Ground and Balloons South Pole Atacama, Chile Balloon Ground In addition, QUBIC at Dome C SPIDER In addition, ABS, CLASS ACTPol à Advanced ACTPol POLARBEAR à Simons Array In addition, QUIJOTE in Canary island, GroundBIRD in Canary island, AMiBA in Hawaii EBEX à EBEX6K LSPE PIPER 58 SPTPolà SPT3G BICEP3 Simons Observatory CMB-S4
  59. 59. B-mode projects (2): Satellites •  LiteBIRD •  Passed initial down-selection by ISAS/JAXA, in phase-A stage •  US participation proposal for NASA MO also passed initial down-selection, in phase-A stage •  Target launch in 2024-2025 •  PIXIE •  NASA small PI-led mission proposal Feb 2011, not selected •  Re-propose to next MIDEX AO (2016 Dec) •  Mission for ESA M5 •  Proposal submitted in Oct 2016 •  Planned launch date of 2029-2030 59 ?
  60. 60. B-mode power spectrum measurements 60Figure by Yuji Chinone Primordial Gravitational waves Lensing
  61. 61. 61 Figure by Yuji Chinone B-mode power spectrum measurements LiteBIRD
  62. 62. Scientific shopping list (1) 62 1)  Cl BB –  inflation and quantum gravity (r, nt ) –  improvement w/ delensing –  lensing B-mode to very low l 2)  Cl EE –  reionization history –  better τ and sum of neutrino masses
  63. 63. Scientific shopping list (2) 63 3)  Power spectrum deviation from ΛCDM –  parity violation in gravity –  quantum loop gravity –  primordial magnetic field –  new source fields for gravitational waves 4)  Bi-spectrum (BBB etc.) – tensor non-Gaussianity – origin of gravitational waves
  64. 64. Scientific shopping list (3) 5)  Non-standard patterns (e.g. bubbles) in the maps à e.g. multiverse 6)  Foreground science 7)  Galactic magnetic field (in particular at large galactic attitude) 8)  Legacy all-sky multi-frequency maps of E-mode/ B-mode/Foregrounds à various astronomical studies 64
  65. 65. Conclusions •  Experimental particle cosmology is exciting ! •  CMB polarization is the new frontier. •  Discoveries await us ! •  Join us ! 65
  66. 66. 66 Backup
  67. 67. LIGO Gravitational Waves Detected 100 Years After Einstein's Prediction ! Feb. 11, 2016 67 https://www.ligo.caltech.edu/news/ ligo20160211 http://www.pbs.org/wgbh/nova/next/physics/ advanced-ligo/
  68. 68. 68
  69. 69. 69

×