On gravitation as a medium property in Maxwell equations
Title: On gravitation as a medium property in Maxwell equations
Speaker: Jai-chan Hwang (IBS-CTPU)
Abstract: The effect of gravity in Maxwell's equations is often treated as a medium property. To an observer with a proper four-vector, the effect of gravity can be arranged as effective polarizations and magnetizations appearing in both the homogeneous and inhomogeneous parts. Modifying the homogeneous part by gravity is inevitable to any observer, and the result cannot be interpreted as the medium property. One such incorrect case is in a Problem of Section 90 in Landau and Lifshitz's "The Classical Theory of Fields."
Detecting Gravitational Wave Background by Electromagnetic Cavity
Title: Detecting Gravitational Wave Background by Electromagnetic Cavity
Speaker: Chan Park (IBS-CTPU)
Abstract: Gravitational wave (GW) detection using electromagnetic (EM) cavities has garnered significant attention in recent years. With ongoing experiments on axion detection using highly sensitive electromagnetic cavity, there is potential to apply these existing facilities to GW detection, opening up a new channel of GW observation. In this talk, we comprehensively examine the principles of GW detection using EM cavities within the framework of general relativity. Furthermore, we propose a detection method for the GW background.
Symmetries and Selection Rules: Optimising Axion Haloscopes for Gravitational Wave Searches
Title: Symmetries and Selection Rules: Optimising Axion Haloscopes for Gravitational Wave Searches
Speaker: Sung Mook Lee (Yonsei University)
Abstract: In the presence of electromagnetic fields, both axions and gravitational waves (GWs) induce oscillating magnetic fields: a potentially detectable fingerprint of their presence. We demonstrate that the response is largely dictated by the symmetries of the instruments used to search for it. Focussing on low mass axion haloscopes, we derive selection rules that determine the parametric sensitivity of different detector geometries to axions and GWs, and which further reveal how to optimise the experimental geometry to maximise both signals. The formalism allows us to forecast the optimal sensitivity to GWs in the range of 100 kHz to 100 MHz for instruments such as ABRACADABRA, BASE, ADMX SLIC, SHAFT, WISPLC, and DMRadio.