String Radiative Backreaction

Abstract

We discuss radiative backreaction for global strings described by the Kalb-Ramond action with an analogous derivation to that for the point electron in classical electrodynamics. We show how local corrections to the equations of motion allow one to separate the self-field of the string from that of the radiation-field. Modifications to this 'local backreaction approximation' circumvent the runaway solutions familiar from electrodynamics, allowing these corrections to be used to evolve string trajectories numerically. Comparisons are made with analytic and numerical radiation calculations from previous work and the merits and limitations of this approach are discussed. Finally, we comment on the relevance of this work to simulations of a cosmological network of global or axion strings. These methods can also be applied to describe graviational, electromagnetic and other forms of string radiative backreaction.