# Prospects for observing extreme-mass-ratio inspirals with LISA

## TL;DR

This paper assesses the potential of LISA to detect extreme-mass-ratio inspirals, estimating event rates, source properties, and measurement precision, thereby highlighting their significance for astrophysics, cosmology, and fundamental physics.

## Contribution

It provides the first detailed estimates of EMRI event rates and parameter measurement precision for the 2.5 Gm LISA baseline, considering astrophysical uncertainties.

## Key findings

- Estimated EMRI event rates for LISA.
- Predicted measurement precision for source parameters.
- Discussion of EMRIs' scientific implications.

## Abstract

One of the key astrophysical sources for the Laser Interferometer Space Antenna (LISA) are the inspirals of stellar-origin compact objects into massive black holes in the centres of galaxies. These extreme-mass-ratio inspirals (EMRIs) have great potential for astrophysics, cosmology and fundamental physics. In this paper we describe the likely numbers and properties of EMRI events that LISA will observe. We present the first results computed for the 2.5 Gm interferometer that was the new baseline mission submitted in January 2017 in response to the ESA L3 mission call. In addition, we attempt to quantify the astrophysical uncertainties in EMRI event rate estimates by considering a range of different models for the astrophysical population. We present both likely event rates and estimates for the precision with which the parameters of the observed sources could be measured. We finish by discussing the implications of these results for science using EMRIs.