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Wonders of the Universe and the Ultimate Theory Quest. Hideo Kodama Cosmophysics Group, Theory Center, KEK, Japan @ KEK 意見交換会 9 September 2011 「 機構 における宇宙観測(コスミック・フロンティア) の推進 について」. Wonders of the Universe in the Prephysics Era.
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Wonders of the Universe and the Ultimate TheoryQuest Hideo Kodama Cosmophysics Group, Theory Center, KEK, Japan @ KEK 意見交換会 9 September 2011 「機構における宇宙観測(コスミック・フロンティア)の推進 について」
Wonders of the Universe in the Prephysics Era Motions of the Sun and planets were the most mysterious and important phenomena in the Universe!! Description became more and more complicated !!! KlaudiosPtolemaios • 『アルマゲスト』(最大の書)MegaleSyntaxistesAstronomias』(天文学大全)
Newtonian Physics The Ultimate Theory in the 17th Cenctury Idealisation& Deep insight Ground-based Experiments Galileo Galilei The Law of Innertia Newtonian Mechanics & Law of Gravity Cosmic Observations Johannes Kepler Three Laws for Planetary Motion Precise Cosmology Predicted the Recurrence of the Halley Comet in 1757 ( 76 yr later)
“The Great Book” in the 20th century ???
Standard Model and Beyond- ground-based physics - • SM is established for physics below 100GeV, but … • Incomplete gauge unification • Mysterious hypercharge structure • Strong CP problem • Mysterious generation repetition • Mysterious mass spectrum • The origin of neutrino masses and the CKM matrix • No dark matter candidate • No quantum theory of gravity
GUT and String Theory- Idealisation and Deep Insight - • GUT + PQ-symmetry+SUSY may resolve many of the mysteries, but … • does not explain the generation repetition, • does not explain the origin of G and representations, • does not provide a quantum theory of gravity. • Superstring theory/M-theory may resolve all the problems and might be the ultimate theory of nature, but … • is still incomplete. • is higher dimensional, and its relation to our 4D universe is yet to be clarified. • Characteristic energy scales of these theories are E &1013TeV. Unreachable Energy Frontier for Ground-based Experiments!!
Cosmic Jets Cosmic Rays Wonders of the Universe left to the 21th Century インフレーション 暗黒時代 現在の宇宙の加速膨張 熱いビッグバン宇宙 Creation of the Universe Dark Energy
Cosmophysics Frontier • Energy frontier • Ultra-high energy cosmic ray: E> 109TeV (Ecm >103TeV) • Inflation: H ¼ E2/Mpl»1010TeV , E »1013TeV • Luminosity frontier • Cosmic jet (GRB): Number flux 1035cm-2s-1 (100GeV, diameter»104 km) cf. Belle 2£ 1034cm-2 s-1 (3.5+8GEV) LHC 1034 cm-2 s-1 (7TeV)
Accuracy frontier (Experimental) • CMB measurements: dT/T »10-7 (Planck) • GW laser interferometers : h » 10-22 (LIGO) Cf. WMAP achievements • mº < 0.44 eV (95% CL) [WMAP+LRG PS + H0] • Neff = 3.46 – 5.20 (68% CL) [WMAP + BAO + H0] • Primordial He: Yp=0.251 – 0.401 (95%CL) [WMAP] • Parity violation: Da = -1.1°+/- 1.3°+/- 1.5°(68%CL) [WMAP] • Constraint on QCD axion parameters
UTQuest by Inflation Probe
Cosmic expansion velocity Inflation Hot Big-Bang Universe Cosmic time Cosmological Inflation • Origin of Big-bang • Flatness problem • Horizon problem • Monopole problem • Origin of cosmic structures Accelerated expansion in the early univese Resolves Inflaton=high scalefield(s) with repulsive gravity The Ultimate Theory
How to probe inflation Recombination Reheating Present Hot Big-Bang U. • During inflation • Quantum fluctuations of the inflaton and the metric are frozen on superhorizon scales. • After inflation • Inflaton fluctuations ) Density fluctuations )CMB anisotropy (T/E-modes) • Primordial GWs ) CMB anisotropy (T/E/B-modes) Length B-mode Quantum Fluctuations timet
Observational Evidences WMAP 7yr data: ns= 0.963+/- 0.014 Flatness of the Universe Scale-invariant spectrum for curvature perturbations
Zoo of Influms Small field models Large field models G-inflation Single inflaton k-inflation Potential-Dominated Chaotic type Hill top type Thermal N-flation Sugra Higgs Natural Linear axion Power-law DBI D-brane Monodromy Multipleinflaton Race-track Sugraaxion Vector/anisotropic Curvaton type Hybrid type
Cosmic fluctuations bring us rich information on inflation • Scalar Perturbations ✓ Power Spectrum ) the shape and slope of the inflation potential ○ Adiabaticity)the number of inflaton fields/ light moduli , the inflation scale ☆Non-gaussianity)the type of inflaton ☆ Statistical anisotropy )anisotropic inflation • Tensor perturbations = gravitational waves ☆ Amplitude) the energy scale of inflation ☆GWPolarisation) CP violation in the gravity sector
Primordial GWs as a robust probe Tensor-Scalar Ratio Primordial GWs are detectable only for high scale inflations. Lyth Bound Primordial GWs are detectable only for large field inflations .
new influm Chaotic influm Small field models require fine-tuning of the initial condition Large field models are more natural !! Race-track model: a KKLT-type string moduli inflation model
Current limit is still large Current limit: r<0.25 (95%CL) [ACT] Planck accurary: r<0.07
r = 2£10-3 is critical Small field models Large field models G-inflation Single inflaton k-inflation Potential-Dominated Chaotic type Hill top type Thermal N-flation Sugra Higgs Natural Linear axion Power-law DBI D-brane Monodromy Multipleinflaton Race-track Sugraaxion Vector/anisotropic Curvaton type Hybrid type
E-mode and B-mode Pure E-mode Pure B-mode b E cosb+ B sinb Lue, Wang, Kamionkowski 1999
E-mode Seljak Scalar Perturbations only produce E-mode
B-mode Tensor perturbations produce both E- and B- modes
Direct measurements of BGW bring more information 黒柳幸子@SI2011
Future GW telescopes can see the reheating processes 黒柳幸子@SI2011
Ground-based Experiments Ultimate Theory Gauge Principle Supersymmetry Idealisation& Deep insight 現在の宇宙 前景放射 CMB 最初の星 Cosmic Observations 宇宙の始まり CMB, GW Precise Cosmology インフレーション ダークエイジ ビッグバン 再結合 銀河形成 再電離 Inflation is an ultimate accelerator!! 宇宙年齢 10-36秒 38万年 1億年 137億年
Constraints Summary Recent CMB observations support predictions of the inflationary universe scenario on LSS of the Universe: Can we construct an inflation model explaining these observational features in the framework of unified theory? • Flatness: |k|<0.01 • Homogeneity • Scalar perturbations • Amplitude • Spectral index: ns¼ 0.96 • Adiabaticity during the period teq < t < trec • Good gaussianity (Cf. CMB anomalies, cold spots, supervoid, …) • Tensor/scalar ratio: r=h2/R2 <0.3. • Reheating • Baryon asymmetry Thermal leptogenesis ) Tr> O(109) GeV [Buchmuller et al 2005] • Gravitino problem Tr < 108 GeV for m3/2>10keV [Kawasaki, Moroi 1995; Kawasaki, Takahashi, Yanagida 2006]
Flatness -0.0175 < K<0.0085 (95%CL: WMAP5yr+BAO+SN) インフレーションが始まる前の空間曲率をki,対応するスケール因子をai,インフレーション終了後(再加熱後)のスケール因子をafとおくと, およびaeq' 2.5£ 10-5より, (Hf =2£ 1014GeV ,Tf' 1016GeV). よって,
Horizon Problem 現在のHubbleホライズンサイズがインフレーションの途中でHubbleホライズンサイズ以下の領域になるためには, これは と同等.よって,
Fluctuations • スカラゆらぎ(曲率ゆらぎ)の振幅: » 5£ 10-5. より正確には [WMAP 5yr] • スペクトル指数: ns = 0.960+0.014-0.013 (95%CL) [WMAP 5yr+BAO+SN] • テンソル/スカラ比: r:=¢h2/¢R2 <0.20 (95%CL) [WMAP5yr + BAO + SN] • 非断熱性: dT vs. d½DM • < 8.6% : axion-type DM • < 2.0% : curvaton-type DM • 非ガウス性:
スペクトルの統計的非等方性 • WMAP constraint gs < 0.3 [Pullen, Kamionkowski 2007] • Planck sensitivity g>0.025 (400/lmax)1.27 [Groeneboomn, Eriksen 2008]
Reheating • バリオン非対称性:nB/ng =(6.10+/- 0.21)£ 10-10 (WMAP3yr) Cf. Thermal leptogenesis)Tr> 3x109GeV [Buchmuller W, Di Bari P, Plumacher M (2005) Ann. Phys. 315:305] • Gravitino問題 [Kawasaki M, Takahashi F, Yanagida 2006;Kawasaki M, Moroi T 1995] • m3/2=100 GeV – 10 TeV (unstable): Thermal production )Tr<106-8GeV (BBN constraint) • 10 keV< m3/2<O(10)GeV (stable, LSP): Tr<107GeV(m3/2/1GeV) (M constraint)