Current status of space gravitational wave antenna DECIGO and B-DECIGO

Seiji Kawamura,Yoshinori Nakayama,Keisuke Taniguchi,Hiroyuki Nakano,Kazunori Kohri,Shinji Mukohyama,Shinji Tsujikawa,Toshifumi Futamase,Shoki Iwaguchi,Masaki Ando,Takashi Hiramatsu,Shinya Kanemura,Mitsuru Musha,Hideki Asada,Jun’Ichi Yokoyama,Tomohiro Ishikawa,Rika Yamada,Yasufumi Kojima,Hideki Ishihara,Motoyuki Saijo,Takahiro Tanaka,Kei Kotake,Izumi Watanabe,Kent Yagi,Kiyotomo Ichiki,Mizuhiko Hosokawa,Masashi Ohkawa,Kouji Nakamura,Shinichi Nakasuka,Atsushi Taruya,Kunihito Ioka,Takeshi Chiba,Satoshi Ikari,Ryuichi Fujita,Takashi Nakamura,Koji Nagano,Akitoshi Ueda,Masaru Shibata,Tomohiro Harada,Ryutaro Takahashi,Naoki Seto,Isao Kawano,Takeshi Takashima,Yuta Michimura,Norichika Sago,Shuichiro Yokoyama,Akito Araya,Motohiro Enoki,Hajime Sotani,Nobuyuki Kanda,Takahiro Ito,Sachiko Kuroyanagi,Ken–Ichi Nakao ,Takeshi Morimoto ,Ken Ueda ,Kei Ichi Maeda ,Ken–Ichi Oohara ,K Agatsuma ,M K Fujimoto ,H Shinkai ,K Hayama ,Feng–Lei Hong ,K Kokeyama ,T Naito ,F Kawazoe ,Y Itoh ,Chul Moon Yoo ,A Takamori ,A Shoda ,S Nagano ,K Nakazawa ,A Nishizawa ,K Tsubono ,S Kobayashi ,K Izumi ,Takashi Satō ,Y Himemoto ,Sachiko Matsushita ,Masa‐Aki Sakagami ,K Somiya ,S Eguchi ,S Sato ,T Akutsu ,N Aritomi ,S Sakai ,Hideya Takahashi ,Z.-H Zhu

doi:10.1093/ptep/ptab019

Abstract

Abstract The Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is a future Japanese space mission with a frequency band of 0.1 Hz to 10 Hz. DECIGO aims at the detection of primordial gravitational waves, which could have been produced during the inflationary period right after the birth of the Universe. There are many other scientific objectives of DECIGO, including the direct measurement of the acceleration of the expansion of the Universe, and reliable and accurate predictions of the timing and locations of neutron star/black hole binary coalescences. DECIGO consists of four clusters of observatories placed in heliocentric orbit. Each cluster consists of three spacecraft, which form three Fabry–Pérot Michelson interferometers with an arm length of 1000 km. Three DECIGO clusters will be placed far from each other, and the fourth will be placed in the same position as one of the other three to obtain correlation signals for the detection of primordial gravitational waves. We plan to launch B-DECIGO, which is a scientific pathfinder for DECIGO, before DECIGO in the 2030s to demonstrate the technologies required for DECIGO, as well as to obtain fruitful scientific results to further expand multi-messenger astronomy.

Highlights

Gravitational waves were detected for the first time by the Laser Interferometer Gravitational-wave Observatory (LIGO) in 2015 [1]
The Japanese Gravitational Wave Community (JGWC) already agreed in 2018 that we regard observations of gravitational waves by KAGRA as the highest priority, and after that, we develop gravitational wave astronomy by Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) and B-DECIGO
B-DECIGO could reveal the formation mechanism of 30-solar-mass black holes, which were detected by LIGO and Virgo, by detecting abundant gravitational waves coming from 10- to 30-solar-mass black hole binaries

Summary

Introduction

Gravitational waves were detected for the first time by the Laser Interferometer Gravitational-wave Observatory (LIGO) in 2015 [1] They found that the gravitational waves came from the merger of a black hole binary that occurred ∼400 Mpc from Earth. After several subsequent detections of gravitational waves from black hole binary inspirals, in 2017, LIGO, together with Virgo, caught gravitational waves emitted from the merger of a neutron star binary [2]. This detection led to successful follow-up observations with electromagnetic waves [3,4].

Objectives

Methods

Conclusion