Probing cosmology with astrophysical gravitational wave background

研究计划的最初目标已经实现。在过去的12个月里，我一直致力于拟议项目的扩展。我已经完成了一篇论文，研究起源于早期宇宙中形成的原始黑洞双星的各向异性引力波背景，并评估了区分引力波双星的原始和天体物理起源的前景。此外，为了验证宇宙尺度的引力，我还继续进行了解析引力波源和星系之间的互相关模型的研究，并通过测量引力波双星的空间聚集的线性偏差来确定引力波双星的起源。除了KAKENHI项目的主题之外，我还参与了与主题间接相关的项目。特别是，我已经完成了一篇论文，探索在早期宇宙中产生磁场的前景。所研究的情况也与引力波的产生有关，并对未来的引力波实验感兴趣。我还发表了一篇论文，讨论了利用伽玛暴进行基础物理学检验的可能性，并研究了LCDM模型的扩展。我已经完成了研究访问，在此期间，我根据所获得的结果发表了特邀演讲，详见本报告后面的章节。

The original goals of the research proposal have been already achieved. During the past 12 months I have worked on extensions of the proposed projects. I have completed a paper studying anisotropic gravitational-wave background originating from primordial black-hole binaries formed in the early universe, and have assessed the prospects of distinguishing the primordial and astrophysical origins of gravitational-wave binaries. Additionally, I have continued working on modeling the cross-correlations between resolved gravitation-wave sources and galaxies with the aim of testing gravity at cosmological scales, as well as establishing the origin of gravitational-wave binaries via measuring the linear bias of their spatial clustering.In addition to the main theme of the KAKENHI project, I have also worked on projects of indirect relevance to the main theme. Particularly, I have completed a paper exploring the prospects of generating magnetic fields in the early universe. The studied scenario is also relevant for gravitation-wave generation, and is of interest for future gravitational-wave experiments. I have also released a paper discussing possible tests of fundamental physics using GRBs, and have studied extensions of the LCDM model.I have completed research visits during which I have delivered invited talks based on the obtained results, as detailed at later sections of this report.