This research project in gravitational physics is largely in support of the Laser Interferometer Gravitational-wave Observatory (LIGO). It will be theoretical, although in many aspects closely related to experiment. In LIGO instrumentation and precision measurement, this project seeks to shed light on approaches to further improve the sensitivity of LIGO interferometers beyond Advanced LIGO, support R&D activities of Advanced LIGO, and explore how future gravitational-wave interferometers can be used to probe quantum mechanical behavior of macroscopic objects. In gravitational-wave-detection methodology, this proposal will further explore a scheme co-invented by the PI and Seiji Kawamura, which circumvents local disturbances to the test masses imposed by the environment, while retaining gravitational-wave signals. In gravitational-wave data analysis, this project seeks strategies that improve the detectability of compact binary systems (consisting black holes and/or neutron stars) by incorporating recent results from numerical relativity, and by optimally combining data from a global network of detectors. In quantum-gravity phenomenology, this project will explore possibilities of searching for quantum foams using astronomical observations.
This project will increase the scientific output of gravitational-wave astronomy by contributing to the short- and long-term improvement of instruments, and by optimizing data analysis strategies; it will formulate strategies that will eventually lead to the experimental proof (or disproof) that quantum mechanical laws also apply to macroscopic (human-sized) objects; it will explore whether and how fundamental quantum fluctuations in space-time can be measured. This project will also have the following broader impacts: (i) It will serve as a training ground for young theoretical physicists, through solving a broad range of physics problems, from experimental design, to data analysis, to theoretical methods in general relativity. (ii) The PI will assume teaching responsibility at Caltech. He plans to update the web-based course in gravitational-wave science that he assisted Thorne in creating. This course has helped train graduate students at Caltech and other universities and institutes, and has made gravitational-wave science accessible to scientists and engineers throughout the world. (iii) The PI will carry out research in collaboration with scientists in Germany, Japan, Russia and China. In particular, the PI expect to serve as a major consultant to the Chinese gravitational-wave program.
