The Japanese space gravitational wave antenna: DECIGO

Abstract

DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. DECIGO is expected to open a new window of observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing various mysteries of the universe such as dark energy, formation mechanism of supermassive black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of three drag-free spacecraft, whose relative displacements are measured by a differential Fabry-Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre-DECIGO first and finally DECIGO in 2024.

Exploring dynamical CP violation induced baryogenesis by gravitational waves and colliders

“…After the first discovery of GWs by Advanced LIGO [3], GWs becomes a new realistic approach to study the EW baryogenesis mechanism by future space-based experiments, such as the approved Laser Interferometer Space Antenna (LISA) [23] (which is assumed to be launched in 2034), Deci-hertz Interferometer Gravitational wave Observatory (DECIGO) [24], Ultimate-DECIGO (U-DECIGO) [25], and Big Bang Observer (BBO) [26]. The SFOPT process in the EW baryogenesis can produce detectable GW signals through three mechanisms: bubble collisions, turbulence, and sound waves [27][28][29][30][31][32][33][34][35][36][37].…”

Gravitational Self-Force Correction to the Innermost Stable Circular Equatorial Orbit of a Kerr Black Hole

“…Circular (timelike) geodesic orbits below the ISCO are unstable under perturbations away from circularity. The ISCO marks the onset of final merger in inspiraling compact-object binaries targeted by gravitational-wave detectors like KAGRA [1], LIGO [2], and Virgo [3], as well as the future missions eLISA [4] and DECIGO [5].…”

Cosmology with space-based gravitational-wave detectors: Dark energy and primordial gravitational waves

“…In the current preconceptual design of the detector [2][3][4], DECIGO and BBO orbit the Sun with a period of one sidereal year, and constitute four clusters, each of which consists of three spacecraft exchanging laser beams with the others. Two of the four clusters are located at the same position to enhance the correlation and hence the sensitivity to a stochastic GW background, and the other two are widely separated from each other on the Earth orbit in order to enhance the angular resolution so that we can easily identify the host galaxy of each NS binary via the electromagnetic follow-up observations [4].…”

“…As for BBO, the sensitivity at high frequencies is limited by beam-pointing-jitter and stray light noises rather than laser shot noise. The noise curve of DECIGO is calculated adopting currentlyproposed design parameters [2,30]. We obtained fitting formula for the sky-averaged noise curve of DECIGO single interferometer …”

“…Future space-based gravitational-wave (GW) detectors such as DECI-hertz Interferometer Gravitational-wave Observatory (DECIGO) [1,2] and Big-Bang Observer (BBO) [3] (see also [4] for updated information) are the most sensitive to GWs in 0.1-1 Hz band and will aim at detecting the primordial GW background, the mergers of intermediate-mass black holes (BH), and a large number of neutron-star (NS) binaries in an inspiraling phase. These GW sources enable us to probe inflation and density perturbation in the early universe [5][6][7][8][9], to measure the cosmic expansion with unprecedented precision [4,10], to investigate the population and formation history of compact binary objects [11], and to test alternative theories of gravity [12][13][14][15].…”