BIMSA >
BIMSA General Relativity Seminar
Celestial choreography of extreme-mass-ratio inspirals in astrophysical environments
Celestial choreography of extreme-mass-ratio inspirals in astrophysical environments
Organizers
Speaker
Kyriakos Destounis
Time
Friday, December 12, 2025 4:30 PM - 5:30 PM
Venue
A3-2-301
Online
Zoom 787 662 9899
(BIMSA)
Abstract
The symphony of the Universe is conducted by a seemingly invisible yet omnipresent force: gravity. Much like the harmonious blend of musical notes, this cosmic choreographer shapes a grand rhythm through gravitational waves—vibrations that ripple through the fabric of space and time and carry vital clues about the cosmos. As we currently listen to these signals through a collective of ground-based interferometers, i.e., the LIGO/Virgo/KAGRA collaboration, spaceborne detectors such as LISA, Taiji, and TianQin, will reveal a dynamic dance of celestial bodies from sources yet unseen. In this talk, I will explore one of the most intricate performers in this cosmic orchestra: extreme-mass-ratio inspirals (EMRIs). These asymmetric binaries, in which a stellar-mass compact object spirals into a supermassive black hole, are among the prime targets for space-based detectors, offering unparalleled insight into strong-field gravity. I will discuss how astrophysical environments may imprint detectable signatures on EMRI waveforms, influence gravitational-wave generation and propagation, and modify the behavior of transient orbital resonances. Particular attention will be given to chaotic dynamics in non-integrable spacetimes, and to how environmental effects might amplify or obscure these features. Together, these considerations highlight both the complexity and the scientific promise of observing astrophysical EMRIs in the low-frequency gravitational-wave band.
Speaker Intro
Kyriakos Destounis studies black holes and gravitational waves. His research covers black–hole binary phenomenology and the modelling of gravitational waves, with particular emphasis on the inspiral stage of coalescing compact objects. Furthermore, he contributes to the field of black–hole spectroscopy, which is currently establishing a robust framework for interpreting the ringdown stage of remnants, and its stability against environments. Kyriakos is a Junior Researcher at the Center for Astrophysics and Gravitation (CENTRA) of Instituto Superior Técnico (IST), in Lisbon, Portugal.