Mechanics of stationary strings: separability of non-dispersive models in a black hole background

Abstract
The problem of equilibrium in a stationary gravitational (and electromagnetic) background is formulated for a macroscopic string model of the general kind applicable to phenomena ranging from ordinary elastic strings to superconducting cosmic strings. A key role is found to be played by the tangent vector given in terms of the Killing vector and the string surface stress momentum-energy tensor. The resulting system is worked out explicitly for string models of the special non-dispersive type that has been shown to take account of the averaged effect of small-scale oscillations in a simple Goto-Nambu model, and that also arises in the more artificial case of string models obtained by dimensional reduction.