LISA’s Sensitivity and Detectability of Higher-Order Modes, Precession in Massive and Intermediate Black Hole Binaries, and Extreme-Mass-Ratio Inspirals

With the promise of increased detection rates and a milli-Hertz sensitivity band, the upcoming space-based gravitational-wave detector LISA is expected to open new frontiers in multi-band gravitational-wave astronomy. This work aims to assess LISA's sensitivity to higher-order modes (HOMs) and the influence of intrinsic parameters such as spin and mass ratio on its detection capability. We investigate the detectability of precession effects in Massive Black Hole Binaries (MBBHs), Intermediate-Mass Black Hole Binaries (IMBHs), and Extreme-Mass-Ratio Inspirals (EMRIs), focusing on the (2,2), (3,2), and (4,2) higher-order modes. The analysis employs Python-based toolkits developed for direct access to and utilization of LISA's sensitivity curve, as well as a visualization framework to examine dominant and subdominant modes across aligned, misaligned, and high-spin configurations. These tools enable efficient evaluation of waveform structures and detectability, supporting future advancements in LISA's data analysis pipelines. Our study underscores the importance of incorporating higher-order modes and spin-precession effects in waveform templates to fully exploit LISA's potential for probing the astrophysics and fundamental physics of black hole binary systems.