******** CTCD/NTHU HEP Seminar ********

Speaker : Prof. Yuki Inoue (NCU)

Title ：Science of CHRONOS Gravitational wave detector in Taiwan

Time ：12:30-13:30, Thursday, 2026/4/30

Place ：R521, 5F, General Building II, Nat'l Tsing Hua Univ.

Host ： Prof. Kingman Cheung (NTHU) & Prof. Norihiro Iizuka (NTHU)

Abstract:
The rapid progress of gravitational-wave astronomy has opened new observational windows on the Universe, yet the frequency band between sub-Hz and a few Hz remains largely unexplored. We present the scientific concept and experimental design of CHRONOS, a Taiwanese gravitational-wave detector targeting this low-frequency regime. CHRONOS is based on a cryogenic torsion-bar antenna equipped with a quantum non-demolition (QND) speed-meter readout, enabling high-sensitivity measurements of differential angular motion induced by gravitational waves.
The detector is designed to operate in the frequency range of 0.1–10 Hz, with a target strain sensitivity of ∼10^−18 1/√Hz at 2 Hz. This band is particularly promising for observing intermediate-mass black hole binaries, stochastic gravitational-wave backgrounds, and potential signatures of primordial gravitational waves. In addition, CHRONOS provides a unique platform for probing fundamental physics, including tests of deviations from Newtonian gravity at meter scales through precision calibration systems.
We discuss the detector configuration, noise budget, and key enabling technologies, including the reduction of coating thermal noise, mitigation of Newtonian noise, and quantum-limited interferometric readout. As a next-generation experiment, CHRONOS will complement existing ground-based detectors such as LIGO, Virgo, and KAGRA, while opening a new observational window in gravitational-wave science and strengthening Taiwan’s role in the global effort.