  A new formulation for the equation of motion of interacting dislocations is
derived. From this solution it is shown that additional coupling forces, of
kinetic and inertial origin, should be considered in Dislocation Dynamics (DD)
simulations at high strain rates. A heuristic modification of this general
equation of motion enables one to introduce retardation into inertial and
elastic forces, in accordance with a progressive rearrangement of fields
through wave propagation. The influence of the corresponding coupling terms and
retardation effects are then illustrated in the case of dislocation dipolar
interaction and coplanar annihilation. Finally, comparison is made between the
modified equation of motion and a precise numerical solution based on the
Peierls-Nabarro Galerkin method. Good agreement is found between the
Peierls-Nabarro Galerkin method and the EoM including retardation effects for a
dipolar interaction. For coplanar annihilation, it is demonstrated that an
unexpected mechanism, involving a complex interplay between the core of the
dislocations and kinetics energies, allows a renucleation from the completely
annihilated dislocations. A description of this phenomenon that could break the
most favourable reaction between dislocations is proposed.
