Title: Search for a stochastic gravitational wave background at 1-5 Hz with Torsion-bar Antenna Show Chinese title

Title: 在1-5赫兹范围内使用扭杆天线搜索随机引力波背景

Abstract: We set the first upper limit on the stochastic gravitational wave (GW) background in the frequency range of $1-5\,\mathrm{Hz}$ using a Torsion-bar Antenna (TOBA). A TOBA is a GW detector designed for the detection of low frequency GWs on the ground, with two orthogonal test masses rotated by the incident GWs. We performed a 24-hour observation run using the TOBA and set upper limits, based on frequentist statistics and Bayesian statistics. The most stringent values are $\Omega_\mathrm{gw}h_0^2 \leq 6.0 \times10^{18}$ (frequentist) and $\Omega_\mathrm{gw}h_0^2 \leq 1.2 \times 10^{20}$ (Bayesian) both at $2.58\,\mathrm{Hz}$, where $h_0$ is the Hubble constant in units of $100\,\mathrm{km/s/Mpc}$ and $\Omega_\mathrm{gw}$ is the GW energy density per logarithmic frequency interval in units of the closure density. Show Chinese abstract

Abstract: 我们首次设定了在频率范围$1-5\,\mathrm{Hz}$内随机引力波（GW）背景的上限，使用的是扭秤天线（TOBA）。 一个 TOBA 是一种设计用于在地面上探测低频 GW 的引力波探测器，具有两个正交的测试质量，会因入射的 GW 而旋转。 我们使用 TOBA 进行了一次 24 小时的观测运行，并基于频率统计和贝叶斯统计设定了上限。 最严格的值为$\Omega_\mathrm{gw}h_0^2 \leq 6.0 \times10^{18}$（频率统计）和$\Omega_\mathrm{gw}h_0^2 \leq 1.2 \times 10^{20}$（贝叶斯统计），均在$2.58\,\mathrm{Hz}$处，其中$h_0$是以$100\,\mathrm{km/s/Mpc}$为单位的哈勃常数，$\Omega_\mathrm{gw}$是以闭合密度为单位的对数频率间隔内的 GW 能量密度。