非ガウス性から探る密度揺らぎの起源と進化

• Project Area: The Physical Origin of the Universe viewed through the Cosmic Background Radiation - from Cosmological Inflation to Dark Ages -
• Project/Area Number: 24111702
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Tohoku University
• Principal Investigator: 高橋 史宜 東北大学, 理学(系)研究科(研究院), 准教授 (60503878)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Project Status: Completed (Fiscal Year 2013)
• Budget Amount: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000); Fiscal Year 2013: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2012: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
• Keywords: 密度揺らぎ / 宇宙背景輻射 / インフレーション / 初期宇宙 / 素粒子論

Research Abstract

Planckの観測発表を受け、密度揺らぎの非ガウス性に対する制限は非常に厳しいものとなった。そこで、カーバトンなどのspectator field模型が満たすべき条件を観測結果発表直後に調べあげ論文として発表した。更に、QCDアクシオンがつくる等曲率ゆらぎとその非ガウス性を解析的及び数値的に求め、この厳しい制限を用いてアクシオンとインフレーションスケールに制限を導くことができた。また等曲率揺らぎの制限を避けるために、QCDアクシオンがインフレーション中に非常に重くなる理論的可能性を追求した。一方、Planck衛星の観測結果を受け、Polynomical chaotic inflationを４次元超重力理論の枠組みで構築した。更に、ごく最近発表のあったBICEP2の結果を説明するHiggs chaotic inflationおよびmulti-natural inflation模型を提唱した。特に、後者においては、通常作るのが非常に困難である大きなrunning spectral indexが生成可能であることを具体的に示し、Planckとのtensionを解く可能性を論じた。このように、現在の宇宙の揺らぎの起源を探ることを第一の目的として研究を進めてきた結果、新しい観測結果と合わせ、その起源の可能性をかなり絞り込むことができた。更に、暗黒物質の有力な候補であるQCDアクシオンに対する制限が非常に厳しいということも、BICEP2の発表後、世界に先駆けて発表することができた。従って、この研究において、学術的な成果を確実にあげ、かつ熾烈な研究競争に勝ったといえる。

Current Status of Research Progress

Reason

25年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

25年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] 7 keV sterile neutrino dark matter from split flavor mechanism (2014)
  • Author(s): Hiroyuki Ishida, Kwang Sik Jeong and Fuminobu Takahashi
  • Journal Title: Physics Letters B Volume: 732 Pages: 196-200
  • DOI: 10.1016/j.physletb.2014.03.044
  • Peer Reviewed
• [Journal Article] The 7 keV axion dark matter and the X-ray line signal (2014)
  • Author(s): Tetsutaro Higaki, Kwang Sik Jeong and Fuminobu Takahashi
  • Journal Title: Physics Letters B Volume: 733 Pages: 25-31
  • DOI: 10.1016/j.physletb.2014.04.007
  • Peer Reviewed
• [Journal Article] Moduli-induced Baryogenesis (2014)
  • Author(s): Koji Ishiwata, Kwang Sik Jeong and Fuminobu Takahashi
  • Journal Title: JHEP Volume: 1402 Issue: 2
  • DOI: 10.1007/jhep02(2014)062
  • Peer Reviewed
• [Journal Article] Chaotic Inflation with Right-handed Sneutrinos after Planck (2014)
  • Author(s): K. Nakayama, F. Takahashi and T. T. Yanagida
  • Journal Title: Phys. Lett. B Volume: 730 Pages: 24-29
  • DOI: 10.1016/j.physletb.2014.01.022
  • Peer Reviewed
• [Journal Article] Axions as Hot and Cold Dark Matter (2014)
  • Author(s): K. S. Jeong, M. Kawasaki and F. Takahashi
  • Journal Title: JCAP Volume: 1402 Issue: 02 Pages: 46-46
  • DOI: 10.1088/1475-7516/2014/02/046
  • Peer Reviewed
• [Journal Article] Longevity Problem of Sterile Neutrino Dark Matter (2014)
  • Author(s): Hiroyuki Ishida, Kwang Sik Jeong, Fuminobu Takahashi
  • Journal Title: Phys. Lett. B Volume: 731 Pages: 242-247
  • DOI: 10.1016/j.physletb.2014.02.048
  • Peer Reviewed
• [Journal Article] New inflation in supergravity after Planck and LHC (2013)
  • Author(s): Fuminobu Takahashi
  • Journal Title: Phys. Lett. B Volume: 727 Issue: 1-3 Pages: 21-26
  • DOI: 10.1016/j.physletb.2013.10.026
  • Peer Reviewed
• [Journal Article] Cosmological constraints on axionic dark radiation from axion-photon conversion in the early Universe (2013)
  • Author(s): T. Higaki, K. Nakayama and F. Takahashi
  • Journal Title: JCAP Volume: 1309 Issue: 09 Pages: 30-30
  • DOI: 10.1088/1475-7516/2013/09/030
  • Peer Reviewed
• [Journal Article] Self-interacting Dark Radiation (2013)
  • Author(s): Kwang Sik Jeong, Fuminobu Takahashi
  • Journal Title: Phys. Lett. B Volume: 725 Issue: 1-3 Pages: 134-138
  • DOI: 10.1016/j.physletb.2013.07.001
  • Peer Reviewed
• [Journal Article] Polynomial Chaotic Inflation in Supergravity (2013)
  • Author(s): K. Nakayama, F. Takahashi and T. T. Yanagida
  • Journal Title: JCAP Volume: 1308 Issue: 08 Pages: 38-38
  • DOI: 10.1088/1475-7516/2013/08/038
  • Peer Reviewed
• [Journal Article] Suppressing Isocurvature Perturbations of QCD Axion Dark Matter (2013)
  • Author(s): Kwang Sik Jeong, Fuminobu Takahashi
  • Journal Title: Phys. Lett. B Volume: 727 Issue: 4-5 Pages: 448-451
  • DOI: 10.1016/j.physletb.2013.10.061
  • Peer Reviewed
• [Journal Article] Moduli-Induced Axion Problem (2013)
  • Author(s): T. Higaki, K. Nakayama and F. Takahashi
  • Journal Title: JHEP Volume: 1307 Issue: 7 Pages: 5-5
  • DOI: 10.1007/jhep07(2013)005
  • Peer Reviewed
• [Journal Article] Isocurvture Constraints and Anharmonic Effects on QCD Axion Dark Matter (2013)
  • Author(s): Takeshi Kobayashi, Ryosuke Kurematsu, Fuminobu Takahashi
  • Journal Title: JCAP Volume: 1309 Issue: 09 Pages: 032-032
  • DOI: 10.1088/1475-7516/2013/09/032
  • Peer Reviewed
• [Journal Article] A Parallel World in the Dark (2013)
  • Author(s): Tetsutaro Higaki, Kwang Sik Jeong and Fuminobu Takahashi
  • Journal Title: JCAP Volume: 1308 Issue: 08 Pages: 031-031
  • DOI: 10.1088/1475-7516/2013/08/031
  • Peer Reviewed
• [Journal Article] Axionic Co-genesis of Baryon, Dark Matter and Dark Radiation (2013)
  • Author(s): Kwang Sik Jeong, Fuminobu Takahashi
  • Journal Title: JHEP Volume: 1304 Issue: 4
  • DOI: 10.1007/jhep04(2013)121
  • Peer Reviewed
• [Journal Article] Non-Gaussianity from Axionic Curvaton (2013)
  • Author(s): M. Kawasaki, T. Kobayashi and F. Takahashi
  • Journal Title: JCAP Volume: 1303 Issue: 03 Pages: 16-16
  • DOI: 10.1088/1475-7516/2013/03/016
  • Peer Reviewed
• [Journal Article] Alchemical Inflation: inflaton turns into Higgs (2012)
  • Author(s): K.Nakayama and F.Takahashi,
  • Journal Title: Journal of Cosmology and Astroparticle Physics Volume: 1211 Issue: 11 Pages: 7-7
  • DOI: 10.1088/1475-7516/2012/11/007
  • Peer Reviewed
• [Journal Article] Higgs, Moduli Problem, Baryogenesis and Large Volume Compactifications (2012)
  • Author(s): Higaki, K. Kamada, Fuminobu Takahashi
  • Journal Title: JHEP Volume: 1209 Issue: 9 Pages: 43-43
  • DOI: 10.1007/jhep09(2012)043
  • Peer Reviewed
• [Journal Article] Dark Radiation and Dark Matter in Large Volume Compactifications (2012)
  • Author(s): Tetsutaro Higaki, Fuminobu Takahashi
  • Journal Title: JHEP Volume: 1211 Issue: 11 Pages: 125-125
  • DOI: 10.1007/jhep11(2012)125
  • Peer Reviewed
• [Presentation] Recent topics in Cosmology (2012)
  • Author(s): Fuminobu Takahashi
  • Organizer: Summer Institute
  • Place of Presentation: Taiwan, Sun-Moon Lake
  • Year and Date: 2012-08-18
  • Invited
• [Presentation] Moduli Cosmology (2012)
  • Author(s): Fuminobu Takahashi
  • Organizer: The 3rd UTQuest workshop
  • Place of Presentation: 北海道帯広市
  • Year and Date: 2012-08-06
  • Invited
• [Presentation] Moduli-induced Baryogenesis
  • Author(s): Fuminobu Takahashi
  • Organizer: 日本物理学会
  • Place of Presentation: 東海大学 湘南キャンパス
• [Presentation] Extended Natural Inflation
  • Author(s): Fuminobu Takahashi
  • Organizer: APC-YITP collaboration: mini-workshop on gravitation and cosmology
  • Place of Presentation: 京都大学基礎物理学研究所
• [Presentation] Cosmological implications for SUSY and its breaking
  • Author(s): Fuminobu Takahashi
  • Organizer: SUSY: Model-building and Phenomenology
  • Place of Presentation: 東京大学 Kavli IPMU
  • Invited
• [Presentation] Planck implications for high energy physics
  • Author(s): Fuminobu Takahashi
  • Organizer: String pheno 2013
  • Place of Presentation: DESY, Hamburg, Germany
  • Invited
• [Presentation] Precision cosmology meets particle physics
  • Author(s): Fuminobu Takahashi
  • Organizer: Higgs and Beyond
  • Place of Presentation: 東北大学
  • Invited