| Name: Sangita Chatterjee |
| Affiliation: Presidency University |
| Conference ID: ASI2026_229 |
| Title: Exploring Dark Matter Imprints in GW Signals from EMRI |
| Abstract Type: Poster |
| Abstract Category: High Energy Phenomena, Fundamental Physics and Astronomy |
| Author(s) and Co-Author(s) with Affiliation: Sangita Chatterjee(Presidency University, 86/1 College Street, Kolkata-700073, WB, India.), Ritaban Chatterjee(Presidency University, 86/1 College Street, Kolkata-700073, WB, India.) |
| Abstract: Extreme- and intermediate-mass ratio inspirals (EMRIs and IMRIs), formed by the gradual inspiral of a compact object into a massive black hole, are prime targets for space-based gravitational-wave detectors because of their long-lived evolution and the accumulation of a large number of gravitational-wave (GW) cycles in the strong-field regime. This makes them uniquely sensitive probes of relativistic dynamics and the matter distribution surrounding massive black holes.
In galactic nuclei hosting massive black holes embedded in dense dark matter environments, a dark matter spike can form if the black hole grows adiabatically compared to the dynamical timescale of the surrounding halo. The presence of such a spike can cause the orbital evolution of an inspiraling compact object to deviate significantly from the vacuum case, leading to observable modifications in the GW signal.
In this work, we study inspirals, the geodesic motion of which is governed by the Kerr spacetime, embedded in a dark matter distribution described by a Navarro–Frenk–White (NFW) profile. The orbital evolution of the compact companion is influenced by gravitational-wave emission, dynamical friction, and mass accretion. We investigate the resulting modifications to the orbital dynamics and quantify the induced GW phase shifts relative to vacuum Kerr inspirals, with particular emphasis on their detectability by the milli-hertz GW detector LISA. We also examine how enhanced environmental drag affects the rate of orbital circularization.
Our work highlights the importance of environmental effects in GW astronomy and indicates that future space-based detectors, such as LISA, may be sensitive to the distribution of dark matter around massive black holes. |
