Possibility of Direct Measurement of the Acceleration of the Universe Using 0.1 Hz Band Laser Interferometer Gravitational Wave Antenna in Space

It may be possible to construct a laser interferometer gravitational wave antenna in space with h_rms~10^-27 at f~0.1 Hz in this century. Using this antenna, (1) typically 10⁵ chirp signals of coalescing binary neutron stars per year may be detected with S/N~10⁴ (2) we can directly measure the acceleration of the universe by a 10 yr observation of binary neutron stars; and (3) the stochastic gravitational waves of Ω_GW>~10^-20 predicted by the inflation may be detected by correlation analysis. Our formula for phase shift due to accelerating motion might be applied for binary sources of LISA.