Gravitational-wave signatures of dark-matter accretion in intermediate mass-ratio inspirals

Massive black holes can grow in the presence of dark-matter environments and form dark-matter spikes with large densities. When a massive black hole within a dark-matter environment is part of an intermediate mass-ratio inspiral, the environmental effects will be impressed onto the system's dynamics. In particular, dynamical friction and accretion effects from the dark-matter distribution acting on the secondary can have measurable impacts on the inspiral rate and gravitational waveform from the system. However, the specific details of the profile have important consequences in determining the magnitude and nature of these effects. Many prior studies that include feedback to the dark-matter distribution considered dark-matter densities that begin with a power-law profile at all allowed radii. However, these profiles include dark-matter particles that would be accreted by the primary. In this talk, I will discuss an updated scheme where the dynamical effects of the dark matter spike are computed with a density consistent with accretion onto the primary. These modifications to the density profile can have appreciable changes to the inspiral rate and emitted gravitational waves.