| Project/Area Number |
17H02875
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Tohoku University |
|---|
Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
石渡 弘治 金沢大学, 数物科学系, 准教授 (40754271)
横崎 統三 東北大学, 理学研究科, 助教 (80779322)
|
|---|
| Project Period (FY) |
2017-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥18,850,000 (Direct Cost: ¥14,500,000、Indirect Cost: ¥4,350,000)
Fiscal Year 2019: ¥6,890,000 (Direct Cost: ¥5,300,000、Indirect Cost: ¥1,590,000)
Fiscal Year 2018: ¥7,150,000 (Direct Cost: ¥5,500,000、Indirect Cost: ¥1,650,000)
Fiscal Year 2017: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
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| Keywords | ダークマター / 初期宇宙 / 極弱粒子 / アクシオン / WISP / 隠れた光子 / ステライルニュートリノ / 素粒子論 / 宇宙物理 |
|---|
| Outline of Final Research Achievements |
We have proposed new cosmological evolution and production process of the weakly interacting slim particles. As a representative result, we proposed a new production mechanism by axions in the scenario where dark photons become dark matter. In particular, it was found that dark photons with extremely low masses, which were difficult to produce, can become cold dark matter. We also find that the cosmological upper bound on the axion decay constant is relaxed significantly by considering the stochastic dynamics of the QCD axion during inflation.
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| Academic Significance and Societal Importance of the Research Achievements |
この宇宙に遍在するダークマターやダークエネルギーの候補である粒子に関して，その宇宙論的な進化および生成過程について詳細に調べることによって，新たに尤もらしい質量領域や将来実験におけるパラメタ－領域を発見することができた。このような新粒子として，ダークフォトンやアクシオンといった非常に軽い質量をもちながら標準理論粒子との相互作用が非常に弱い粒子があげられる。
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