Development of Cosmology and Astrophysics with a primordial magnetic field

2015 Fiscal Year Final Research Report

• Project/Area Number: 25871055
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Astronomy; Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Ibaraki University (2014-2015); National Astronomical Observatory of Japan (2013)
• Principal Investigator: Yamazaki Dai 茨城大学, 大学教育センター, 准教授 (90531822)
• Research Collaborator: Ichiki Kiyotomo 名古屋大学, 大学院理学研究科 宇宙論研究室, 講師 (10534480) ; Takahashi Keitarou 熊本大学, 自然科学研究科, 准教授 (80547547) ; Kusakabe Motohiko Center for Astrophysics, Department of Physics, University of Notre Dame, Postdoctoral Research Fellow ; Kajino Toshitaka 国立天文台, 理論研究部, 准教授 (20169444) ; Mathews Grant. J. Center for Astrophysics, Department of Physics, University of Notre Dame, Professor ; Cheoun Myung-Ki Department of Physics, Soongsil University, Professor
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 宇宙背景放射 / ビッグバン元素合成 / 磁場

Outline of Final Research Achievements

We study effects of a primordial magnetic field (PMF) on the cosmology, and make clear that a PMF enhances the cosmic expansion rate and the sound speed of the cosmic fluid. We, also illustrate that,
(1) the big bang nucleosynthesis (BBN) with a primordial magnetic field (PMF) can deduce the lithium abundance consisted with the observations, (2) the first peek is temperature fluctuations of the cosmic microwave background (CMB) is shifted to larger scale and its amplitude is suppressed by the PMF, (3) the amplitude of the matter power spectrum (MPS) on smaller scales is suppressed by a PMF, (4) the amplitude of the polarization anisotropies of the CMB from the weak lensing effects is suppressed by a PMF, (5)a PMF affect the constraint of the cosmological parameters, specifically the dark matter and baryon density.

Free Research Field

宇宙論・宇宙物理学