| Project/Area Number |
19J22167
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| Research Category |
Grant-in-Aid for JSPS Fellows
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| Allocation Type | Single-year Grants |
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| Section | 国内 |
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| Review Section |
Basic Section 15010:Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics
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| Research Institution | National Astronomical Observatory of Japan (2020-2021)
The University of Tokyo (2019) |
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Principal Investigator |
LUO Yudong 国立天文台, 科学研究部, 特別研究員(PD)
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| Project Period (FY) |
2019-04-25 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2021: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2020: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2019: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Primordial Black hole / r-process / Big Bang Nucleosynthesis / Magnetic Field / Screening effect |
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| Outline of Research at the Start |
In this project, we mainly focus on the fluctuated primordial magnetic field evolution and its impact on BBN. For the first time a comprehensive study of primordial nucleosynthesis with fluctuated PMF will be carried out. Especially a multi-zone BBN code with fluctuated PMF background will be developed to clarify the evolution of PMF and its interaction with particles. The results will lead to a systematic MHD (magneto-hydrodynamical) study in early universe, together with primordial elements observation and CMB spectrum, it will be used to constrain PMF generation mechanism and its evolution.
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| Outline of Annual Research Achievements |
In the most precise treatment of electromagnetic cascade spectrum, I included all feasible photodisintegration reactions and combine them with updated cross section data. I carried out accurate nucleosynthesis calculation and obtained a the reliable constraint on the PBH fraction among all dark matter component. Moreover, I investigated the mass function of PBHs in critical collapse model (i.e., PBHs formed via critical phenomena of gravitational collapse) and the impact on 3He abundance. In the past, the critical collapse mass function is thought of being practically indistinguishable from the monochromatic mass function. However, we show that the 3He abundance is sensitive to even small amounts of PBHs within the low-mass tail in the critical collapse mass function, which indicated that the nucleosynthesis can be a powerful tool to probe the extended mass function of PBHs. This work is publish on the Journal of Cosmology and Astrophysics.
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| Research Progress Status |
令和3年度が最終年度であるため、記入しない。
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| Strategy for Future Research Activity |
令和3年度が最終年度であるため、記入しない。
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