Session D04: Third Generation Gravitational Wave Detectors

Third-generation gravitational-wave detectors - how we will reach the edge of the Universe

The detection of gravitational waves from binary black hole and binary neutron star systems suggests that many such sources will be observed by the current generation of detectors. These sources will, however, be mostly confined to the local universe (z < 1), and many will have a signal to noise ratio just above the detection threshold. In this talk I will discussion the the next generation of ground-based instruments, such as the Einstein Telescope and Cosmic Explorer, which will be sensitive enough to detect binary system throughout the Universe. These detectors will yield a wealth of information about the population of sources as a function of cosmic time, and will reveal many local sources with high signal to noise ratios.   

The scientific potential of third-generation gravitational-wave detectors

The discoveries of gravitational waves from binary black hole and binary neutron star coalescences suggest these sources will be observed in large numbers by currently operating advanced detectors. Thanks to these observations, individual systems and the underlying population can be characterized. However advanced detectors will only be sensitive to sources within a redshift of \textasciitilde 1. By contrast, the next generation of ground-based instruments, such as the Einstein Telescope and Cosmic Explorer, will access a large fraction of the universe. These observatories will, for example, detect 10\textasciicircum 5 binary black holes per year, many of which with large signal-to-noise ratios, up to redshift of \textasciitilde 10. At the same time, these new instruments will significantly increase the probability of detecting rare or weak sources. In this talk I will describe the scientific potential of proposed third-generation gravitational-wave detectors.   

SOGRO: Superconducting Tensor Detector for Mid-Frequency Gravitational Waves

Detection of gravitational waves (GWs) from binary black holes (BHs) and binary neutron stars by advanced laser interferometers has opened a new window of astronomical observation. Many conceivable sources such as intermediate-mass BH binaries and white dwarf binaries, as well as inspiraling stellar-mass BH binaries, would emit GWs below 10 Hz. It is highly desirable to open a new window in the infrasound frequency band below 10 Hz. We propose to construct a mid-frequency tensor detector by combining six magnetically levitated superconducting test masses. Seismic and Newtonian gravity noise are serious obstacles in constructing terrestrial GW detectors at sub-Hz frequencies. The proposed detector is capable of rejecting the seismic noise to one part in 10$^{\mathrm{9}}$ by its common-mode rejection characteristic, and can reject the near-field Newtonian gravity noise to a sufficient degree by its full-tensor nature. Such a detector is equally sensitive to GWs coming from anywhere in the sky, and is capable of resolving the source direction and wave polarization. I will present the design concept of a new mid-frequency detector, named SOGRO, which could reach a strain sensitivity of 10$^{\mathrm{-19}}$-10$^{\mathrm{-21}}$ Hz$^{\mathrm{-1/2}}$ at 0.1-10 Hz.