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Thermal history of the Universe and generation of gravitational waves in physics beyond the Standard Model of particle physics

Research Project

Project/Area Number 20K22344
Research Category

Grant-in-Aid for Research Activity Start-up

Allocation TypeMulti-year Fund
Review Section 0203:Particle-, nuclear-, astro-physics, and related fields
Research InstitutionTohoku University

Principal Investigator

Yamada Masaki  東北大学, 学際科学フロンティア研究所, 助教 (20871106)

Project Period (FY) 2020-09-11 – 2022-03-31
Project Status Completed (Fiscal Year 2021)
Budget Amount *help
¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2021: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2020: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Keywords宇宙の熱史 / バリオン数の非対称性 / 重力波 / 暗黒物質 / インフレーション / 物質反物質非対称性 / ダークマター / バリオン数の生成 / ブラックホール
Outline of Research at the Start

インフレーション後からビッグバン元素合成までの熱史に関する研究を通して、暗黒物質の生成や重力波の放射機構などを理解することを目的とする。特に、インフラトンの崩壊によって生じた高エネルギー粒子が従う方程式を数値的に解くことによって熱平衡化の過程を計算し、宇宙の最高温度を定量的に決定する。また、このときに暗黒物質の生成の効果も取り入れることによって、それが非熱的に生成される可能性を探求する。一方で、今後の重力波観測によって初期宇宙が探査できる時代がくると期待されている。これを受けて、宇宙初期における非自明なダイナミクスから放射される重力波のスペクトルを古典的格子計算によって数値計算する。

Outline of Final Research Achievements

The origin of baryon asymmetry is a long-standing mystery in cosmology. One of the possible mechanisms to generate baryon asymmetry is the decay of right-handed neutrinos in the early Universe. In the present study, we have revealed that almost any asymmetry can be converted to baryon asymmetry via the interaction associated with the right-handed neutrinos. This opens a broader possibility for the generation of baryon asymmetry in physics beyond the Standard Model. Moreover, we have discussed theoretical implications of recently reported signals of a dark-matter direct detection experiment and a pulsar-timing array experiment and have pointed out that they are related to other astrophysical observations. These works have provided a new insight into the thermal history of the Universe.

Academic Significance and Societal Importance of the Research Achievements

宇宙の歴史のなかで、我々を構成する通常の物質の起源については未だに謎に包まれている。一方で、素粒子のニュートリノ振動の観測は右巻きニュートリノの存在を理論的に示唆している。本研究では、この右巻きニュートリノの質量がある広い範囲に入っていれば、宇宙初期に存在する任意の保存量がバリオン数(物質)に転換されることを示した。これにより、物質の起源を説明するシナリオとしてより広い可能性が開かれた。また、研究期間中に報告された暗黒物質探査実験や重力波観測実験の結果を受けてその理論的な解釈を議論し、現在の観測によって宇宙の謎の解明につながりつつあることを明らかにした。

Report

(3 results)
  • 2021 Annual Research Report   Final Research Report ( PDF )
  • 2020 Research-status Report
  • Research Products

    (21 results)

All 2022 2021 2020 Other

All Int'l Joint Research (4 results) Journal Article (7 results) (of which Int'l Joint Research: 5 results,  Peer Reviewed: 7 results,  Open Access: 6 results) Presentation (9 results) (of which Int'l Joint Research: 8 results,  Invited: 4 results) Remarks (1 results)

  • [Int'l Joint Research] Tsung-Dao Lee Institute(中国)

    • Related Report
      2021 Annual Research Report
  • [Int'l Joint Research] CERN/EPFL(スイス)

    • Related Report
      2021 Annual Research Report
  • [Int'l Joint Research] DESY(ドイツ)

    • Related Report
      2021 Annual Research Report
  • [Int'l Joint Research] Shanghai Jiao Tong University(中国)

    • Related Report
      2020 Research-status Report
  • [Journal Article] Baryon Asymmetric Universe from Spontaneous CP Violation2022

    • Author(s)
      Kohei Fujikura、Yuichiro Nakai、Ryosuke Sato、Masaki Yamada
    • Journal Title

      Journal of High Energy Physics

      Volume: 04 Issue: 4 Pages: 105-105

    • DOI

      10.1007/jhep04(2022)105

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Trapping effect for QCD axion dark matter2021

    • Author(s)
      Nakagawa Shota、Takahashi Fuminobu、Yamada Masaki
    • Journal Title

      Journal of Cosmology and Astroparticle Physics

      Volume: 2021 Issue: 05 Pages: 062-062

    • DOI

      10.1088/1475-7516/2021/05/062

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Wash-In Leptogenesis2021

    • Author(s)
      Domcke Valerie、Kamada Kohei、Mukaida Kyohei、Schmitz Kai、Yamada Masaki
    • Journal Title

      Physical Review Letters

      Volume: 126 Issue: 20 Pages: 201802-201802

    • DOI

      10.1103/physrevlett.126.201802

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Gravitational waves and dark radiation from dark phase transition: Connecting NANOGrav pulsar timing data and hubble tension2021

    • Author(s)
      Nakai Yuichiro、Suzuki Motoo、Takahashi Fuminobu、Yamada Masaki
    • Journal Title

      Physics Letters B

      Volume: 816 Pages: 136238-136238

    • DOI

      10.1016/j.physletb.2021.136238

    • Related Report
      2021 Annual Research Report 2020 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] A natural and simple UV completion of the QCD axion model2021

    • Author(s)
      Yamada Masaki、Yanagida Tsutomu T.
    • Journal Title

      Physics Letters B

      Volume: 816 Pages: 136267-136267

    • DOI

      10.1016/j.physletb.2021.136267

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Cosmic Birefringence Triggered by Dark Matter Domination2021

    • Author(s)
      Nakagawa Shota、Takahashi Fuminobu、Yamada Masaki
    • Journal Title

      Physical Review Letters

      Volume: 127 Issue: 18 Pages: 181103-181103

    • DOI

      10.1103/physrevlett.127.181103

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] What if ALP dark matter for the XENON1T excess is the inflaton2021

    • Author(s)
      Fuminobu Takahashi, Masaki Yamada, Wen Yin
    • Journal Title

      Journal of High Energy Physics

      Volume: 152 Issue: 1 Pages: 1-1

    • DOI

      10.1007/jhep01(2021)152

    • Related Report
      2020 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Presentation] Leptoflavorgenesis: baryon asymmetry of the Universe from lepton flavor violation2022

    • Author(s)
      山田將樹
    • Organizer
      New observational windows on the high-scale origin of matter-antimatter asymmetry
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Cosmic Birefringence Triggered by Dark Matter Domination2022

    • Author(s)
      山田將樹
    • Organizer
      FY2021 学術変革領域研究「ダークマター」シンポジウム
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Cosmic Birefringence Triggered by Dark Matter Domination2021

    • Author(s)
      山田將樹
    • Organizer
      PPC 2021: XIV International Workshop on Interconnections between Particle Physics and Cosmology
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Cosmic Birefringence Triggered by Dark Matter Domination2021

    • Author(s)
      山田將樹
    • Organizer
      26th International Symposium on Particle Physics, String Theory, and Cosmology
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Cosmic Birefringence Triggered by Dark Matter Domination2021

    • Author(s)
      山田將樹
    • Organizer
      Cambridge High Energy Workshop 2021
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Cosmic Birefringence Triggered by Dark Matter Domination2021

    • Author(s)
      山田將樹
    • Organizer
      The XXVIII International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2021)
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Cosmic Birefringence Triggered by Dark Matter Domination2021

    • Author(s)
      山田將樹
    • Organizer
      基研研究会 素粒子物理学の進展2021
    • Related Report
      2021 Annual Research Report
  • [Presentation] NANOGrav and first-order phase transition in the early Universe and its implication to H0 tension2020

    • Author(s)
      Masaki Yamada
    • Organizer
      KEK-PH Lectures and Workshops 2020 (KEK-Cosmo GW)
    • Related Report
      2020 Research-status Report
    • Int'l Joint Research / Invited
  • [Presentation] Present status of axion theories and searches and ALP DM interpretation of the XENON1T excess2020

    • Author(s)
      Masaki Yamada
    • Organizer
      Kashiwa DM symposium 2020
    • Related Report
      2020 Research-status Report
    • Int'l Joint Research / Invited
  • [Remarks] 宇宙背景放射の偏光面の回転を説明するアクシオンの運動機構の提唱

    • URL

      https://www.tohoku.ac.jp/japanese/2021/10/press20211029-02.html

    • Related Report
      2021 Annual Research Report

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Published: 2020-09-29   Modified: 2023-01-30  

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