Establishing Gravitational Wave Cosmology

• Project/Area Number: 23340058
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: The University of Tokyo
• Principal Investigator: YOKOYAMA Jun'ichi 東京大学, 理学(系)研究科(研究院), 教授 (50212303)
• Co-Investigator(Renkei-kenkyūsha): SETO Naoki 京都大学, 理学研究科, 助教 (80462191) ; TARUYA Atsushi 京都大学, 基礎物理学研究所, 准教授 (40334239)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥19,500,000 (Direct Cost: ¥15,000,000、Indirect Cost: ¥4,500,000); Fiscal Year 2014: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2013: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000); Fiscal Year 2012: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000); Fiscal Year 2011: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
• Keywords: 重力波 / 宇宙論 / インフレーション / 位相的欠陥 / 相転移 / DECIGO / BICEP2 / 宇宙マイクロ波背景放射 / 原始ブラックホール / コズミックストリング / Bモード偏光 / 宇宙ひも / テンソルゆらぎ / 超弦理論

Outline of Final Research Achievements

This project aimed to study a new formalism to clarify cosmology of the early Unvierse directly using gravitational waves as a new channel of observation and successful achieved it. We have succeeded in presenting a new scheme to probe the early Universe using not only curvature perturbations but also tensor perturbations or quantum gravitational waves for the purpose of selecting the appropriate inflationary universe model among the most general framework in which field equations are of second order. We have also developed a numerical code to simulate the evolution of the scalar field system in a three dimensional lattice and calculated spectrum of gravitational radiation from them in various circumstances. We have also clarified to what extent the future space-based laser interferometer DECIGO can probe the thermal history of the early Universe. Combining all these results, I have fully accomplished what I intended to do.

Research Products

• [Journal Article] Effects of thermal fluctuations on thermal inflation (2015)
  • Author(s): Takashi Hiramatsu, Yuhei Miyamoto, and Jun'ichi Yokoyama
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 3 Issue: 03 Pages: 0-18
  • DOI: 10.1088/1475-7516/2015/03/024
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Reheating processes after Starobinsky inflation in old-minimal supergravity (2015)
  • Author(s): Takahiro Terada, Yuki Watanabe, Yusuke Yamada and Jun'ichi Yokoyama
  • Journal Title: Journal of High Energy Physics Volume: - Issue: 2 Pages: 0-25
  • DOI: 10.1007/jhep02(2015)105
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Can a spectator scalar field enhance inflationary tensor mode? (2015)
  • Author(s): Tomohiro Fujita, Jun'ichi Yokoyama, Shuichiro Yokoyama
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 043E01 Issue: 4 Pages: 1-12
  • DOI: 10.1093/ptep/ptv037
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Prospects of determination of reheating temperature after inflation by DECIGO (2015)
  • Author(s): Kuroyanagi Sachiko, Nakayama Kazunori and Yokoyama Jun'ichi
  • Journal Title: PTEP Volume: 2015 Issue: 1 Pages: 13E02-0
  • DOI: 10.1093/ptep/ptu176
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Effects of cosmic strings with delayed scaling on CMB anisotropy (2015)
  • Author(s): Kohei kamada, Yuhei Miyamoto, Daisuke Yamauchi, and Jun'ichi Yokoyama
  • Journal Title: PHYSICAL REVIEW D Volume: 90 Issue: 8 Pages: 1-8
  • DOI: 10.1103/physrevd.90.083502
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Primordial black holes from temporally enhanced curvature perturbation (2014)
  • Author(s): Suyama Teruaki, Wu Yi-Peng and Yokoyama, Jun'ichi
  • Journal Title: Physical Review Volume: D90 Issue: 4 Pages: 043514-043514
  • DOI: 10.1103/physrevd.90.043514
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Topological inflation from the Starobinsky model in supergravity (2014)
  • Author(s): Kamada, Kohei and Yokoyama, Jun'ichi
  • Journal Title: Physical Review Volume: D90 Issue: 10 Pages: 103520-103520
  • DOI: 10.1103/physrevd.90.103520
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Inflation: 1980-201X (2014)
  • Author(s): Yokoyama, Jun'ichi
  • Journal Title: PTEP Volume: 2014 Issue: 6 Pages: 6B103-0
  • DOI: 10.1093/ptep/ptu081
  • Peer Reviewed / Open Access
• [Journal Article] Langevin description of gauged scalar fields in a thermal bath (2014)
  • Author(s): Y.Miyamoto, H.Motohashi, T.Suyama, J.Yokoyama
  • Journal Title: Physical Review D Volume: 印刷中
  • Peer Reviewed
• [Journal Article] Identifying the most crucial parameters of the initial curvature profile for primordial black hole formation (2013)
  • Author(s): Tomohiro Nakama, Tomohiro Harada, A. G. Polnarev, Jun'ichi Yokoyama
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 2013 Issue: 01 Pages: 037-037
  • DOI: 10.1088/1475-7516/2014/01/037
  • Peer Reviewed
• [Journal Article] Graceful exit from Higgs G-inflation (2013)
  • Author(s): K.Kamada, T.Kobayashi, T.Kunimitsu, M.Yamaguchi, J.Yokoyama
  • Journal Title: Physical Review D Volume: 88 Issue: 12 Pages: 1-12
  • DOI: 10.1103/physrevd.88.123518
  • Peer Reviewed
• [Journal Article] Gravitational modulated reheating and non-Gaussianity in supergravity R^2 inflation (2013)
  • Author(s): Y.Watanabe, J.Yokoyama
  • Journal Title: Physical Review D Volume: 87 Issue: 10
  • DOI: 10.1103/physrevd.87.103524
  • Peer Reviewed
• [Journal Article] Magneto-reheating constraints from curvature perturbations (2013)
  • Author(s): C.Ringeval, T.Suyama and J.Yokoyama
  • Journal Title: JCAP Volume: 1309 Issue: 09 Pages: 020-020
  • DOI: 10.1088/1475-7516/2013/09/020
  • Peer Reviewed
• [Journal Article] Primordial Spikes from Wrapped Brane Inflation (2013)
  • Author(s): T.Kobayashi and J.Yokoyama,
  • Journal Title: JCAP Volume: 1302 Issue: 02 Pages: 5-5
  • DOI: 10.1088/1475-7516/2013/02/005
  • Peer Reviewed
• [Journal Article] Cosmology based on f(R) Gravity admits 1 eV Sterile Neutrinos (2013)
  • Author(s): H. Motohashi, A. A. Starobinsky and J. Yokoyama
  • Journal Title: Physical Review Letters Volume: 110 Issue: 12 Pages: 1-5
  • DOI: 10.1103/physrevlett.110.121302
  • Peer Reviewed
• [Journal Article] Consequences of a stochastic approach to the conformal invariance of inflationary correlators (2012)
  • Author(s): H. Motohashi, T. Suyama and J. Yokoyama
  • Journal Title: Physical Review D Volume: 86 Issue: 12 Pages: 1-10
  • DOI: 10.1103/physrevd.86.123514
  • Peer Reviewed
• [Journal Article] Higgs condensation as an unwanted curvaton (2012)
  • Author(s): T.Kunimitsu and J.Yokoyama
  • Journal Title: Physical Review D Volume: 86 Issue: 8 Pages: 83541-83541
  • DOI: 10.1103/physrevd.86.083541
  • Peer Reviewed
• [Journal Article] Resonant Signatures of Heavy Scalar Fields in the Cosmic Microwave Background (2012)
  • Author(s): 齋藤遼、中島正裕、高水裕一、横山順一
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 1211 Issue: 11 Pages: 36-36
  • DOI: 10.1088/1475-7516/2012/11/036
  • Peer Reviewed
• [Journal Article] Self-consistent initial conditions for primordial black hole formation (2012)
  • Author(s): APolnarev, T.Nakama and J.Yokoyama
  • Journal Title: JCAP Volume: 1209 Issue: 09 Pages: 27-27
  • DOI: 10.1088/1475-7516/2012/09/027
  • Peer Reviewed
• [Journal Article] Metric perturbation from inflationary magnetic field and generic bound on inflation models (2012)
  • Author(s): Teruaki Suyama, Jun'ichi Yokoyama
  • Journal Title: Physical Review D Volume: 86 Issue: 2 Pages: 1-7
  • DOI: 10.1103/physrevd.86.023512
  • Peer Reviewed
• [Journal Article] Evading the pulsar constraints on the cosmic string tension (2012)
  • Author(s): K.Kamada, Y.Miyamoto and J.Yokoyama
  • Journal Title: JCAP Volume: 1210 Issue: 10 Pages: 23-23
  • DOI: 10.1088/1475-7516/2012/10/023
  • Peer Reviewed
• [Journal Article] Phase transition and monopole production in supergravity inflation (2012)
  • Author(s): K.Kamada, K.Nakayama}, J.'i.Yokoyama
  • Journal Title: Physical Review D Volume: 85 Issue: 4 Pages: 43503-43503
  • DOI: 10.1103/physrevd.85.043503
  • Peer Reviewed
• [Journal Article] Generalized Higgs inflation (2012)
  • Author(s): Kohei Kamada, Tsutomu Kobayashi, Tomo Takahashi, Masahide Yamaguchi, Jun'ichi Yokoyama
  • Journal Title: Phys.Rev Volume: D86 Issue: 2 Pages: 23504-23504
  • DOI: 10.1103/physrevd.86.023504
  • Peer Reviewed
• [Journal Article] Primordial non-Gaussianities of gravitational waves in the most general single-field inflation model (2011)
  • Author(s): X. Gao, T. Kobayashi, M. Yamaguchi and J. Yokoyama
  • Journal Title: Physical Review Letter Volume: 107 Issue: 21 Pages: 211301-211301
  • DOI: 10.1103/physrevlett.107.211301
  • Peer Reviewed
• [Journal Article] Temporal enhancement of super-horizon curvature perturbations from decays of two curvatons and its cosmological consequences (2011)
  • Author(s): 須山輝明、横山順一
  • Journal Title: Physical Review D Volume: 84 Issue: 8 Pages: 1-17
  • DOI: 10.1103/physrevd.84.083511
  • Peer Reviewed
• [Journal Article] Generalized G-inflation : Inflation with the most general second-order field equations (2011)
  • Author(s): Tsutomu Kobayashi, Masahide Yamaguchi, Jun'ichi Yokoyama
  • Journal Title: Prog. Theor. Phys Volume: 126 Issue: 3 Pages: 511-529
  • DOI: 10.1143/ptp.126.511
  • NAID: 110008790436
  • Peer Reviewed
• [Presentation] Discussion for the Future Direction of Inflationary Cosmology (2015)
  • Author(s): Yokoyama Jun'ichi
  • Organizer: B-mode Cosmology Workshop
  • Place of Presentation: KEK
  • Year and Date: 2015-02-19
  • Invited
• [Presentation] Inflationary Magnetogenesis (2014)
  • Author(s): Yokoyama Jun'ichi
  • Organizer: Primordial Universe After Planck
  • Place of Presentation: パリ天体物理学研究所
  • Year and Date: 2014-12-17
  • Invited
• [Presentation] Gravitational Waves: Near Future, Far Future (2014)
  • Author(s): Yokoyama Jun'ichi
  • Organizer: CosPA2014
  • Place of Presentation: オークランド大学
  • Year and Date: 2014-12-11
  • Invited
• [Presentation] 原始重力波直接検出への期待 (2014)
  • Author(s): 横山順一
  • Organizer: 日本物理学会秋季大会
  • Place of Presentation: 佐賀大学
  • Year and Date: 2014-09-19
  • Invited
• [Presentation] Prospects of determination of T_R by DECIGO (2014)
  • Author(s): Yokoyama Jun'ichi
  • Organizer: COSMO2014
  • Place of Presentation: シカゴ大学会議場
  • Year and Date: 2014-08-26
• [Presentation] G inflation (2013)
  • Author(s): J. Yokoyama
  • Organizer: APCosPA winter school and workshop
  • Place of Presentation: Taiwan University、台北、中華人民共和国
  • Invited
• [Presentation] Reheating after inflation (2012)
  • Author(s): J. Yokoyama
  • Organizer: APCosPA winter school and workshop
  • Place of Presentation: 台湾大学、台北、中華民国
  • Invited
• [Presentation] Gravitational modulated reheating in R^2 inflation
  • Author(s): 横山順一
  • Organizer: Cosmological Perturbations Post Planck
  • Place of Presentation: ヘルシンキ大学（フィンランド）
  • Invited
• [Presentation] Toward the quest for the ultimate theory of the universe by CMB
  • Author(s): 横山順一
  • Organizer: CMB2013
  • Place of Presentation: 沖縄科学技術大学院大学（沖縄県）
  • Invited
• [Presentation] Toward GW detection under non-Gaussian noises
  • Author(s): 横山順一
  • Organizer: 重力波データ解析ブートキャンプ
  • Place of Presentation: 大阪市立大学 梅田サテライト（大阪府）
• [Presentation] Fine feature in the primordial power spectrum from wrapped brane inflation
  • Author(s): 横山順一
  • Organizer: アジア太平洋物理学会議APPC12
  • Place of Presentation: 幕張国際会議場（千葉県）
• [Presentation] ALMA and variation of the fundamental constants of physics
  • Author(s): 横山順一
  • Organizer: 東大フォーラムALMAワークショップ
  • Place of Presentation: チリ大学（チリ）
  • Invited
• [Presentation] Cosmology of the Higgs field
  • Author(s): 横山順一
  • Organizer: PASCOS2013
  • Place of Presentation: 国立台湾大学国際会議場（台湾）
  • Invited
• [Presentation] Confronting non-Gaussian statistics in gravitational wave data analysis
  • Author(s): 横山順一
  • Organizer: 新学術領域重力波天体シンポジウム
  • Place of Presentation: 東京工業大学（東京都）
• [Presentation] Higgs condensation as an unwanted curvaton
  • Author(s): J. Yokoyama
  • Organizer: COSMO2012
  • Place of Presentation: ITP, 北京、中華人民共和国
• [Presentation] Higgs condensation as an unwanted curvaton
  • Author(s): J. Yokoyama
  • Organizer: string cosmology workshop
  • Place of Presentation: 幕別グランビリオ会議場（北海道）
• [Presentation] 宇宙論における理論的未解決問題
  • Author(s): 横山順一
  • Organizer: HSC研究会
  • Place of Presentation: 国立天文台（東京都）
  • Invited
• [Presentation] Generalized G inflation
  • Author(s): J. Yokoyama
  • Organizer: First LeCosPA symposium
  • Place of Presentation: 台湾大学LeCosPA研究所、台北、中華民国
  • Invited
• [Presentation] Cosmological constraints on primordial black holes
  • Author(s): J. Yokoyama
  • Organizer: QCD in the LHC era/Egypt-Japan workshop on the early Universe
  • Place of Presentation: MTI University、カイロ、エジプト
  • Invited
• [Presentation] f(R) gravity and neutrino mass
  • Author(s): J. Yokoyama
  • Organizer: CosPA2011
  • Place of Presentation: 北京大学、北京、中華人民共和国
  • Invited
• [Presentation] Issues on f(R) cosmology
  • Author(s): J. Yokoyama
  • Organizer: DENET-IAP conference on dark energy
  • Place of Presentation: パリ天体物理学研究所、パリ、フランス共和国
  • Invited
• [Presentation] G inflation and generalized G inflation
  • Author(s): J. Yokoyama
  • Organizer: Preplanckian inflation workshop
  • Place of Presentation: ミネソタ大学、ミネアポリス、アメリカ合衆国
  • Invited
• [Presentation] G-inflation
  • Author(s): J. Yokoyama
  • Organizer: Sorvey APC conference
  • Place of Presentation: APC、パリ、フランス共和国
  • Invited
• [Presentation] G inflation and its nongaussianity
  • Author(s): J. Yokoyama
  • Organizer: Cosmological nongaussianity workshop
  • Place of Presentation: ミシガン州立大学、アナーバー、アメリカ合衆国
  • Invited
• [Book] 宇宙と素粒子のなりたち (2013)
  • Author(s): 糸山浩司 南部陽一郎 横山順一 川合光
  • Total Pages: 168
  • Publisher: 京都大学学術出版会
• [Book] こころを学ぶ (2013)
  • Author(s): ダライラマ14世 横山順一ほか
  • Total Pages: 258
  • Publisher: 講談社
• [Remarks] 横山順一教授が日本物理学会論文賞を受賞
  • URL: https://www.s.u-tokyo.ac.jp/ja/news/1900/
• [Remarks] 横山順一教授が井上学術賞を受賞
  • URL: http://www.s.u-tokyo.ac.jp/ja/info/3726/
• [Remarks] 横山順一教授が日本物理学会論文賞を受賞
  • URL: http://www.s.u-tokyo.ac.jp/info.html?id=4059
• [Remarks] Gインフレーションの提唱
  • URL: http://research.kek.jp/people/hkodama/UTQuestHP/RHL_YokoyamaJun'ichi.html
• [Remarks] アインシュタインは修正されるか？
  • URL: http://www.s.u-tokyo.ac.jp/ja/press/2013/08.html