We review some aspects of few-body encounters between binaries and single stars. In particular we focus on (i) the rate of formation of binaries in three-body encounters; and (ii) the treatment of adiabatic encounters.
The rate of formation of three-body binaries is easily estimated to order of magnitude, but a quantitative estimate is a difficult undertaking. We demonstrate some of the software available, and how its output has to be processed to solve this problem. Then we describe a new, completely numerical approach to the same problem.
The near-invariance of the binding energy of the binary is a well known feature of distant encounters with a hard binary, but the theoretical foundations of this result are not well understood. Furthermore a naive calculation can yield a null result in cases of importance (e.g. an initially circular binary), and we summarise some recent advances in this field.