In this paper we show that a change in the signs of some of the metric components of the solution of the field equations for the classical cosmic string results in a solution which we interpret as a time-dependent wall composed of tachyons. We show that the walls have the property of focusing the paths of particles which pass through them. As an illustration of this focusing, we demonstrate the results of a simple simulation of the interaction between one such tachyon wall and a rotating disk of point masses. This interaction leads to the temporary formation of spiral structures. These spiral structures exist for a time on the order of one galactic rotation.
Green, K. and Cocke, W. John (2003), A solution to Einstein’s field equations for a tachyonic gas: possible astrophysical applications. [Electronic version]. Retrieved [insert date], from Fisher Digital Publications: http://fisherpub.sjfc.edu/math_facpub/3/