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

TL;DR

DECIGO and B-DECIGO are planned space-based gravitational wave observatories aiming to detect primordial waves, measure cosmic expansion, and predict neutron star mergers, with B-DECIGO serving as a technology demonstrator before DECIGO's launch.

Contribution

This paper reviews the current status and scientific objectives of DECIGO and B-DECIGO, highlighting their design, goals, and planned deployment in the 2030s.

Findings

DECIGO aims to detect primordial gravitational waves.

B-DECIGO will demonstrate key technologies for DECIGO.

The observatories will enhance multi-messenger astronomy.

Abstract

Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is the 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 be 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 the heliocentric orbit. Each cluster consists of three spacecraft, which form three Fabry-Perot Michelson interferometers with an arm length of 1,000 km. Three clusters of DECIGO will be placed far from each other, and the fourth cluster will be placed in the same position as one of the three clusters to obtain the correlation signals for the detection of the primordial gravitational waves. We plan to launch B-DECIGO, which is a scientific pathfinder of DECIGO, before DECIGO in the 2030s to demonstrate the technologies required for DECIGO, as well as to obtain fruitful scientific results to further expand the multi-messenger astronomy.