Ayaka Shoda

Search for a Stochastic Gravitational-wave Background using a pair of Torsion-bar Antennas

We have set a new upper limit on the stochastic gravitational-wave background using two prototype torsion-bar antennas (TOBAs). A TOBA is a low-frequency gravitational-wave detector with bar-shaped test masses rotated by the tidal force of gravitational waves. As a result of simultaneous 7-hour observations with TOBAs in Tokyo and Kyoto in Japan, our upper limit with a confidence level of 95% is

Mirror actuation design for the interferometer control of the KAGRA gravitational wave telescope

{\mathrm{\ensuremath{\Omega}}}_{\mathrm{gw}}{h}_{0}^{2}l1.9\ifmmode\times\else\texttimes\fi{}{10}^{17}

Characterization of the room temperature payload prototype for the cryogenic interferometric gravitational wave detector KAGRA

at 0.035--0.830 Hz, where

Active damping performance of the KAGRA seismic attenuation system prototype

{h}_{0}

Improving parameter estimation accuracy with torsion-bar antennas

is the Hubble constant in units of

Ground Based Low-Frequency Gravitational-wave Detector With Multiple Outputs

100\text{ }\text{ }\mathrm{km}/\mathrm{s}/\mathrm{Mpc}

Search for a Stochastic Gravitational-wave Background with Torsion-bar Antennas

and

Search for a stochastic gravitational wave background at 1–5 Hz with a torsion-bar antenna

{\mathrm{\ensuremath{\Omega}}}_{\mathrm{gw}}

Seismic cross-coupling noise in torsion pendulums

is the gravitational-wave energy density per logarithmic frequency interval in units of the closure density. We successfully updated the upper limit and extended the explored frequency band.

Development of KAGRA Algorithmic Library (KAGALI)

KAGRA is a 3-km cryogenic interferometric gravitational wave telescope located at an underground site in Japan. In order to achieve its target sensitivity, the relative positions of the mirrors of the interferometer must be finely adjusted with attached actuators. We have developed a model to simulate the length control loops of the KAGRA interferometer with realistic suspension responses and various noises for mirror actuation. Using our model, we have designed the actuation parameters to have sufficient force range to acquire lock as well as to control all the length degrees of freedom without introducing excess noise.