Unveiling the Dark Side of the Universe: Novel Approach to Gravitational-Wave Millilensing

Gravitational lensing is a phenomenon where intervening objects bend and magnify light, first predicted by Einstein’s theory of general relativity in 1915. However, it wasn’t until the 1970s that the first observational evidence of gravitational lensing was discovered. Since then, scientists have made great strides in studying this phenomenon, which provides a unique way to study the distribution of matter in the universe.

In recent years, gravitational-wave lensing has become an area of intense interest. Gravitational-wave astronomy is a rapidly advancing field that allows us to study the cosmos by observing ripples in spacetime caused by massive objects. Gravitational waves were first detected in 2015 by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and have since opened up a new window to observe the universe.

Our CUHK gravitational-wave team, with Anna Liu, a PhD student at the Chinese University of Hong Kong, as the leading author, recently published a research article titled “Exploring the hidden Universe: A novel phenomenological approach for recovering arbitrary gravitational-wave millilensing configurations.” The article presents a new approach to study millilensing, a specific form of gravitational lensing that can split a gravitational wave signal into multiple copies.

The approach offers a more accurate and efficient tool for studying the distribution of matter in the universe using gravitational-wave signals. Current models for gravitational-wave millilensing are limited and cannot account for complex lensing scenarios. The approach is model-independent, meaning it can recover arbitrary lens configurations without the need for extensive computational modeling. It is also computationally efficient, making it suitable for large-scale studies.

The proposed approach has potential applications for studying complex lens configurations, such as dark matter subhalos and MACHOs. With gravitational-wave lensing observations becoming more feasible, this new method can provide a powerful tool for studying the distribution of matter in the universe and testing our understanding of gravity.

In conclusion, Anna Liu and our CUHK gravitational-wave team have developed a new approach for studying millilensing, a specific form of gravitational lensing that can split a gravitational wave signal into multiple copies. With this novel phenomenological approach, we can study complex lens configurations and potentially unlock new insights into the distribution of matter in the universe, including dark matter subhalos and MACHOs. This research builds upon the legacy of Einstein and we hope it will open up new possibilities for gravitational-wave astronomy. We are excited to see the future applications of this approach, as it might help uncover and the impact it will have on our understanding of the universe.

The research is now published in the Monthly Notices of Royal Astronomical Society (MNRAS)
Link: https://doi.org/10.1093/mnras/stad1302