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2016 Fiscal Year Annual Research Report

Multifaceted Study of the Physics of the Inflationary Universe

Planned Research

Project AreaWhy does the Universe accelerate? - Exhaustive study and challenge for the future -
Project/Area Number 15H05888
Research InstitutionKyoto University

Principal Investigator

佐々木 節  京都大学, 基礎物理学研究所, 教授 (70162386)

Co-Investigator(Kenkyū-buntansha) 横山 順一  東京大学, 大学院理学系研究科(理学部), 教授 (50212303)
高橋 智  佐賀大学, 工学(系)研究科(研究院), 准教授 (60432960)
山口 昌英  東京工業大学, 理学院, 教授 (80383511)
Project Period (FY) 2015-06-29 – 2020-03-31
Keywordsインフレーション宇宙 / 宇宙論的揺らぎ / 宇宙論的重力波 / 宇宙の再加熱 / 宇宙論的非ガウス揺らぎ
Outline of Annual Research Achievements

H28年度は,インフレーション宇宙のダイナミックスやそれから生ずる様々な現象について,これまでにない新しい知見が得られ,発見があった。以下はその主な成果である。
1.インフレーション宇宙のダイナミックス:インフレーション後の再加熱期における重力的粒子生成を詳しく調べ、模型によっては従来の見積もりに比べてはるかに効率的な粒子生成が起こることを発見した(中山)。LIGOが検出した初の重力波イベントは、インフレーション宇宙を起源とする原始ブラックホール連星の合体で生じたものであるというシナリオを提唱した(須山,横山修,佐々木)。宇宙論的二次摂動論を展開し、原始ブラックホールの観測制限との比較により、広域な周波数域の原始重力波の振幅に対して、定量的な上限を与えた(須山)。また、インフレーション宇宙起源で、理論的に整合的な原始宇宙磁場の形成が可能であることを初めて示した(佐々木)。
2.観測的検証:観測で示唆される強いスケール依存性をもつCMBスペクトルの双極的非対称性の無矛盾な模型を構成した(高橋,佐々木)。初期ゆらぎの非ガウス性によるインフレーションモデルの峻別に関して、将来の広視野銀河サーベイによって現在のCMB観測より強い制限が得られることを明らかにした(横山修)。
3.理論の追求:無限階微分を含む非局所的な理論の超対称性化を試み、その超対称性が破れると質量公式が成り立たないことを示した(山口)。ドジッター時空中に電子対生成を調べ、電場の強さによっては誘起電流が負になる(=電気伝導率の値が負になる)ことを示した(横山順)。最も一般的なスカラー・テンソル理論(ホルンデスキー理論)の枠組みで、特異点のない宇宙モデルの安定性を調べ、すべての解が勾配不安定性を持つことを示した(小林)。

Current Status of Research Progress
Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

メンバー各自がそれぞれの役割を着実に果たして研究を進めており、新たな知見も多く得られている。

Strategy for Future Research Activity

H29年度中にメンバー全員が集まり、これまでの成果を俯瞰し総括する。そして、世界の中での我々の研究の進展状況・位置を明確にする。それに基づいて、今後の方向性を議論する。

  • Research Products

    (27 results)

All 2017 2016 Other

All Int'l Joint Research (6 results) Journal Article (11 results) (of which Int'l Joint Research: 7 results,  Peer Reviewed: 11 results,  Acknowledgement Compliant: 11 results) Presentation (9 results) (of which Int'l Joint Research: 9 results,  Invited: 9 results) Remarks (1 results)

  • [Int'l Joint Research] University of Lancaster/University of Portsmouth/University of London, Queen Mary(英国)

    • Country Name
      UNITED KINGDOM
    • Counterpart Institution
      University of Lancaster/University of Portsmouth/University of London, Queen Mary
    • # of Other Institutions
      2
  • [Int'l Joint Research] Chinese Academy of Science/Hong Kong U of Science and Technology(中国)

    • Country Name
      CHINA
    • Counterpart Institution
      Chinese Academy of Science/Hong Kong U of Science and Technology
  • [Int'l Joint Research] University of California, Berkeley/Stanford University/University of Chicago(米国)

    • Country Name
      U.S.A.
    • Counterpart Institution
      University of California, Berkeley/Stanford University/University of Chicago
    • # of Other Institutions
      3
  • [Int'l Joint Research] University of Paris 7/University of Tours(フランス)

    • Country Name
      FRANCE
    • Counterpart Institution
      University of Paris 7/University of Tours
  • [Int'l Joint Research] APCTP/POSTECH/Institute for Basic Science(韓国)

    • Country Name
      KOREA (REP. OF KOREA)
    • Counterpart Institution
      APCTP/POSTECH/Institute for Basic Science
  • [Int'l Joint Research]

    • # of Other Countries
      5
  • [Journal Article] Vacuum State of the Dirac Field in de Sitter Space and Entanglement Entropy2017

    • Author(s)
      Sugumi Kanno, Misao Sasaki, Takahiro Tanaka
    • Journal Title

      Journal of High Energy Physics (JHEP)

      Volume: 1703 Pages: 068

    • DOI

      10.1007/JHEP03(2017)068

    • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
  • [Journal Article] Consistency relation and inflaton field redefinition in the delta N formalism2017

    • Author(s)
      Guillem Domenech, Jinn-Ouk Gong, Misao Sasaki
    • Journal Title

      Physics Letters B

      Volume: 769 Pages: 413,417

    • DOI

      10.1016/j.physletb.2017.04.014

    • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
  • [Journal Article] Strongly scale-dependent CMB dipolar asymmetry from super-curvature fluctuations2016

    • Author(s)
      Christian Byrnes, Guillem Domenech, Misao Sasaki, Tomo Takahashi
    • Journal Title

      Journal of Cosmology and Astroparticle Physics (JCAP)

      Volume: 1612 Pages: 020

    • DOI

      10.1088/1475-7516/2016/12/020

    • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
  • [Journal Article] Global adiabaticity and non-Gaussianity consistency condition2016

    • Author(s)
      Antonio Enea Romano (Antioquia U. & Kyoto U., Yukawa Inst., Kyoto), Sander Mooij (Chile U., Beauchef), Misao Sasaki
    • Journal Title

      Physics Letters B

      Volume: 761 Pages: 119, 124

    • DOI

      10.1016/j.physletb.2016.08.025

    • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
  • [Journal Article] Primordial Black Hole Scenario for the Gravitational-Wave Event GW1509142016

    • Author(s)
      Misao Sasaki, Teruaki Suyama, Takahiro Tanaka, Shuichiro Yokoyama
    • Journal Title

      Physical Review Letters

      Volume: 117 Pages: 061101

    • DOI

      10.1103/PhysRevLett.117.061101

    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Nonlocal N=1 supersymmetry2016

    • Author(s)
      Tetsuji Kimura, Anupam Mazumdar, Toshifumi Noumi, Masahide Yamaguchi
    • Journal Title

      Journal of High Energy Physics (JHEP)

      Volume: 1610 Pages: 022

    • DOI

      10.1007/JHEP10(2016)022

    • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
  • [Journal Article] Supermassive black holes formed by direct collapse of inflationary perturbations2016

    • Author(s)
      Tomohiro Nakama, Teruaki Suyama, Jun'ichi Yokoyama
    • Journal Title

      Physical Review D

      Volume: 94 Pages: 103522

    • DOI

      10.1103/PhysRevD.94.103522

    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Constraining equilateral-type primordial non-Gaussianities from imaging surveys2016

    • Author(s)
      Ichihiko Hashimoto, Shuntaro Mizuno, Shuichiro Yokoyama
    • Journal Title

      Physical Review D

      Volume: 94 Pages: 043532

    • DOI

      10.1103/PhysRevD.94.043532

    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Electroweak Vacuum Stabilized by Moduli during/after Inflation2016

    • Author(s)
      Yohei Ema, Kyohei Mukaida, Kazunori Nakayama
    • Journal Title

      Physics Letters B

      Volume: 761 Pages: 419,423

    • DOI

      10.1016/j.physletb.2016.08.046

    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Fermionic Schwinger effect and induced current in de Sitter space2016

    • Author(s)
      Takahiro Hayashinaka, Tomohiro Fujita, Jun'ichi Yokoyama
    • Journal Title

      Journal of Cosmology and Astroparticle Physics (JCAP)

      Volume: 1607 Pages: 010

    • DOI

      10.1088/1475-7516/2016/07/010

    • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
  • [Journal Article] Late-time quantum backreaction of a very light nonminimally coupled scalar2016

    • Author(s)
      Drazen Glavan, Tomislav Prokopec, Tomo Takahashi
    • Journal Title

      Physical Review D

      Volume: 94 Pages: 084053

    • DOI

      10.1103/PhysRevD.94.084053

    • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
  • [Presentation] Signatures from inflationary massive gravity2017

    • Author(s)
      Misao Sasaki
    • Organizer
      Testing Gravity 2017
    • Place of Presentation
      Vancouver, Canada
    • Year and Date
      2017-01-27 – 2017-01-27
    • Int'l Joint Research / Invited
  • [Presentation] Gravitational waves as a probe of physics beyond the standard model2017

    • Author(s)
      Kazunori Nakayama
    • Organizer
      Physics in LHC and the early Universe
    • Place of Presentation
      Tokyo, Japan
    • Year and Date
      2017-01-10 – 2017-01-10
    • Int'l Joint Research / Invited
  • [Presentation] Primordial Black Hole Scenario for the Gravitational-Wave Event GW1509142017

    • Author(s)
      Teruaki Suyama
    • Organizer
      Workshop on primordial black hole, Academia Sinica
    • Place of Presentation
      Taipei, Taiwan
    • Year and Date
      2017-01-06 – 2017-01-06
    • Int'l Joint Research / Invited
  • [Presentation] Inflation and Beyond2016

    • Author(s)
      Misao Sasaki
    • Organizer
      NCTS Annual Theory Meeting 2016: Particles, Cosmology and String
    • Place of Presentation
      Hsinchu, Taiwan
    • Year and Date
      2016-12-07 – 2016-12-07
    • Int'l Joint Research / Invited
  • [Presentation] Inflation2016

    • Author(s)
      Misao Sasaki
    • Organizer
      The 13th International Symposium on Cosmology and Particle Astrophysics (CosPA 2016)
    • Place of Presentation
      Sydney, Australia
    • Year and Date
      2016-11-30 – 2016-11-30
    • Int'l Joint Research / Invited
  • [Presentation] How can we probe inflation and the origin of density fluctuations?2016

    • Author(s)
      Tomo Takahashi
    • Organizer
      The 26th Workshop on General Relativity and Gravitation (JGRG 26)
    • Place of Presentation
      Osaka, Japan
    • Year and Date
      2016-10-27 – 2016-10-27
    • Int'l Joint Research / Invited
  • [Presentation] Inflationary Magnetogenesis with Broken Local U(1) Symmetr2016

    • Author(s)
      Misao Sasaki
    • Organizer
      IF-YITP GR+HEP+Cosmo International Symposium VI
    • Place of Presentation
      Phitsanulok, Thailand
    • Year and Date
      2016-08-05 – 2016-08-05
    • Int'l Joint Research / Invited
  • [Presentation] SUSY inflation? What else?'2016

    • Author(s)
      Jun'ichi Yokoyama
    • Organizer
      The 24th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2016)
    • Place of Presentation
      Melborne, Australia
    • Year and Date
      2016-07-06 – 2016-07-06
    • Int'l Joint Research / Invited
  • [Presentation] Inflationary Cosmology: present status and future issues2016

    • Author(s)
      Misao Sasaki
    • Organizer
      2016 Annual Meeting of the Chinese Physical Society, Division of Gravitation and Relativistic Astrophysics
    • Place of Presentation
      Changsha, China
    • Year and Date
      2016-06-29 – 2016-06-29
    • Int'l Joint Research / Invited
  • [Remarks] 加速宇宙ーインフレーション

    • URL

      http://www2.yukawa.kyoto-u.ac.jp/~accel_a01/index.html

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Published: 2018-01-16   Modified: 2022-10-14  

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