title: Torsion-bar antenna for low-frequency gravitational-wave observations.
abstract: We propose a novel type of gravitational-wave antenna, formed by two bar-shaped test masses and laser-interferometric sensors to monitor their differential angular fluctuations. This antenna has a fundamental sensitivity to low-frequency signals below 1 Hz, even with a ground-based configuration. In addition, it is possible to expand the observation band to a lower limit determined by the observation time, by using modulation and up-conversion of gravitational-wave signals by rotation of the antenna. The potential sensitivity of this antenna is superior to those of current detectors in a 1 mHz-10 Hz frequency band and is sufficient for observations of gravitational waves radiated from in-spiral and merger events of intermediate-mass black holes.
authors.affiliation: Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan. ando@scphys.kyoto-u.ac.jp
authors.forename: Masaki
authors.initials: M
authors.lastname: Ando
authors.forename: Koji
authors.initials: K
authors.lastname: Ishidoshiro
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Kent
authors.initials: K
authors.lastname: Yagi
authors.forename: Wataru
authors.initials: W
authors.lastname: Kokuyama
authors.forename: Kimio
authors.initials: K
authors.lastname: Tsubono
authors.forename: Akiteru
authors.initials: A
authors.lastname: Takamori