Online seminar

Our next online seminar will take place on March 23 at 5:30 PM (CET), featuring a talk by Verónica Vázquez-Aceves (Kavli Institute for Astronomy and Astrophysics at Peking University).

Inspiraling Systems in Dense Stellar Environments: Formation, Dynamics, and Detection Challenges

Verónica Vázquez-Aceves is a Postdoctoral Researcher at the Kavli Institute for Astronomy and Astrophysics at Peking University. Her research focuses on gravitational‑wave astrophysics and stellar dynamics, particularly on the formation mechanisms of gravitational‑wave sources for space‑based detectors such as LISA, TianQin and Taiji. She works on extreme and extremely large mass‑ratio inspirals (EMRIs and XMRIs), the formation and signatures of intermediate‑mass‑ratio inspirals (IMRIs) in globular clusters, and the detectability of these systems with future space‑based missions. Her work combines analytical modeling, numerical simulations, and dynamical studies to understand how complex astrophysical environments shape gravitational‑wave signals.

Within the next decade, at least two space‑based gravitational‑wave detectors will be operational: the Laser Interferometer Space Antenna (LISA) and one of the Chinese missions, TianQin or Taiji. These observatories will uncover a rich population of inspiraling systems whose properties reflect both their astrophysical formation channels and the complex dynamical environments in which they evolve. I will begin by outlining the main formation scenarios of inspiraling systems and discuss how these pathways shape their characteristic signatures and the challenges they pose for accurate waveform modeling.

I will then focus on the Galactic Center, where the dense stellar environment surrounding Sgr A* naturally supports the formation of extreme and extremely large mass‑ratio inspirals (EMRIs and XMRIs). While isolated inspirals have been extensively studied, the dynamical interplay between coexisting EMRIs and XMRIs has remained largely unexplored. We investigate the coupled evolution of an EMRI and an XMRI orbiting Sgr A*, showing that long‑range gravitational interactions between the two systems can induce measurable perturbations in their trajectories, leading to waveform deviations relative to the isolated case. These perturbations accumulate over observational timescales and may imprint detectable signatures in the data streams of LISA, TianQin, and Taiji.

Our results highlight the importance of incorporating multi‑body inspiral environments into next‑generation waveform modeling and search strategies. Accounting for these effects will be essential for fully exploiting the scientific potential of future space‑based gravitational‑wave missions.