Exploring magnetic properties of neutron-star matter through gravitational waves

• Project/Area Number: 18K03622
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 15010:Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Osaka University
• Principal Investigator: Baiotti Luca 大阪大学, インターナショナルカレッジ, 准教授 (00574047)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2020: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: Neutron stars / Binary mergers / Equations of state / Gravitational waves / Magnetic fields / Resistivity

Outline of Final Research Achievements

We have investigated one of the most mysterious objects in the universe: neutron stars. They are the highest-density objects in the universe and those with the highest magnetic fields. Their density reaches up to several times the nuclear density, where quarks are probably non-confined into hadrons (free quark matter). These densities allow us to study physics that is not reproducible in any terrestrial lab. Our research connected this ultra-high-density physics to observations of gravitational waves emitted by binary systems of neutron stars. We proposed ways to infer the presence of free quarks in neutron stars

Academic Significance and Societal Importance of the Research Achievements

学術的には、本プロジェクトは中性子星の中でクロスオーバーによって生じるフリークォーク物質について、重力波の観測を用いた実用的な研究への道を開いた。社会的には、人類の特権である知的充足感の源の一つである宇宙への理解を広げる努力に少しは貢献できたと思う。

Research Products

• [Journal Article] Merger and Postmerger of Binary Neutron Stars with a Quark-Hadron Crossover Equation of State (2022)
  • Author(s): Huang Yong-Jia、Baiotti Luca、Kojo Toru、Takami Kentaro、Sotani Hajime、Togashi Hajime、Hatsuda Tetsuo、Nagataki Shigehiro、Fan Yi-Zhong
  • Journal Title: Physical Review Letters Volume: 129 Issue: 18 Pages: 181101-181101
  • DOI: 10.1103/physrevlett.129.181101
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Gravitational waves from binary neutron stars (2021)
  • Author(s): Baiotti Luca
  • Journal Title: Arabian Journal of Mathematics Volume: 1 Issue: 1 Pages: 1-14
  • DOI: 10.1007/s40065-021-00357-7
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Gravitational waves from neutron star mergers and their relation to the nuclear equation of state (2019)
  • Author(s): BAIOTTI Luca
  • Journal Title: Progress in Particle and Nuclear Physics Volume: 109 Pages: 1037141-49
  • DOI: 10.1016/j.ppnp.2019.103714
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Gravitational waves from binary neutron stars (2021)
  • Author(s): Luca BAIOTTI
  • Organizer: International Online Workshop on Relativistic Astrophysics and Gravitation, IWRAG-2021
  • Int'l Joint Research / Invited
• [Presentation] Binary-compact-stars, gravitational waves and equation of state (2018)
  • Author(s): Luca Baiotti
  • Organizer: Meeting on Nuclear Astrophysics, RIKEN, Wako
  • Int'l Joint Research / Invited
• [Presentation] Gravitational waves and the equation of state of binary compact stars (2018)
  • Author(s): Luca Baiotti
  • Organizer: 5th Joint Meeting of the APS Division of Nuclear Physics and the Physical Society of Japan, Waikoloa
  • Int'l Joint Research / Invited