  We present a drag force model for evolving chaotic few-body interactions with
the inclusion of orbital energy losses, such as tidal dissipation and
gravitational wave (GW) emission. The main effect from such losses is the
formation of two-body captures, that for compact objects result in GW mergers,
and for stars lead to either compact binaries, mergers or disruptions. Studying
the inclusion of energy loss terms in few-body interactions is therefore likely
to be important for modeling and understanding the variety of transients that
soon will be observed by current and upcoming surveys. However, including
especially tides in few-body codes has been shown to be technically difficult
and computationally heavy, which has lead to very few systematic tidal studies.
In this paper we derive a drag force term that can be used to model the effects
from tidal, as well as other, energy losses in few-body interactions, if the
two-body orbit averaged energy loss is known a priori. This drag force model is
very fast to evolve, and gives results in agreement with other approaches,
including the impulsive and affine tide approximations.
