Research:

Dynamical interactions can bring a binary with large initial orbital separation into a close pericenter passage, leading to efficient GW emission and a final merger. As a progenitor stage of these mergers, highly eccentric compact object binaries may commonly exist in our Universe.

In this work, we examine the stochastic GW background (GWB) from highly eccentric, stellar-mass sources in the mHz band. Our findings suggest that these binaries can contribute a substantial GW power spectrum, potentially exceeding the LISA instrumental noise at 3~7 mHz.

For eccentric compact object binaries with large orbital seperation, their GW emission happens mostly near the pericenter passage, creating a unique, burst-like signature in the waveform.

Based on our estimation, there will be 3-45 bursting binary black holes in the Milky Way, with hundreds to thousands of GW bursts detected during the LISA mission.

Using the general relativistic precession pattern in the GW signal, we can enhance the measurement accuracy of GW sources' peculiar acceleration by a factor of ~100, providing that the binary has moderate eccentricity.

This finding can help us identify the GW sources' acceleration in the milli-hertz gravitational wave band, even if they are as far as 1pc away from a supermassive black hole in the galactic center. With the improved acceleration measurement, we can better understand where these GW sources live and how they formed.

The GW signal from Double White Dwarfs (DWDs) in hierarchical triple systems can be distorted. We may misidentify them as other kinds of GW sources, such as binary black holes, binary neutron stars, or even primordial black holes. Because of the large population of DWDs in the milli-hertz GW band, we need to pay attention to this problem and avoid misleading interpretations in future space gravitational wave detections, such as LISA.

Binary black holes can live in a gaseous environment (for example, AGN disks), which makes their orbital evolution quite different from other GW sources in the vacuum. Our numerical simulation shows the role of gas in the evolution of these GW sources, as well as how long it will take us to distinguish the effect of the gas.