# Dissipative Evolution of Unequal Mass Binary-Single Interactions and its Relevance to Gravitational Wave Detections

## TL;DR

This paper develops an analytical framework to estimate the formation rates of compact binaries through energy-loss mechanisms like gravitational wave emission during three-body interactions, with implications for gravitational wave detection.

## Contribution

It introduces a new formalism to calculate cross sections of two-body captures in binary-single interactions considering energy dissipation, enhancing understanding of dynamical binary formation.

## Key findings

- Two-body gravitational wave captures can form during three-body interactions.
- The estimated rates are relevant for Advanced LIGO detections.
- Formation of eccentric binaries has observable consequences.

## Abstract

We present a study on binary-single interactions with energy loss terms such as tidal dissipation and gravitational wave emission added to the equation-of-motion. The inclusion of such terms leads to the formation of compact binaries that form during the three-body interaction through two-body captures. These binaries predominantly merge relative promptly at high eccentricity, with several observable and dynamical consequences to follow. Despite their possibility for being observed in both present and upcoming transient surveys, their outcomes are not firmly constrained. In this paper we present an analytical framework that allows to estimate the cross section of such two-body captures, which permits us to study how the corresponding rates depends on the initial orbital parameters, the mass hierarchy, the type of interacting objects, and the energy dissipation mechanism. This formalism is applied here to study the formation of two-body gravitational wave captures, for which we estimate absolute and relative rates relevant to Advanced LIGO detections. It is shown that two-body gravitational wave captures should have compelling observational implications if a sizable fraction of detected compact binaries are formed via dynamical interactions.