ABSTRACT
A cosmic string, like any other concentration of mass and energy, acts as the source of a gravitational field. Because cosmic strings are extended objects, this gravitational field will affect not only the motion of nearby particles but also the trajectory of the string itself, and so calculating the gravitational field of even an isolated cosmic string in otherwise empty space can pose a complicated nonlinear problem. Nonetheless the gravitational field should not simply be ignored, as there are indications that it can have important effects on the dynamics and energetics of strings. For example, gravitational radiation is thought to be the dominant energy-loss mechanism for loops [Vil85], while it has been suggested that the radiation of momentum from an asymmetric loop could accelerate the loop to relativistic bulk velocities, giving rise to a so-called ‘gravitational rocket effect’ [VV85].
