Time Evolution in Open String Theory

TL;DR

This paper presents an iterative method to construct time-dependent solutions in open string theory, describing tachyon dynamics and D-brane decay, linking them to boundary conformal field theories.

Contribution

It introduces a novel iterative procedure for modeling tachyon rolling and D-brane decay in open string theory, connecting solutions to boundary conformal field theories.

Findings

Constructed time-dependent tachyon solutions with initial position and velocity parameters.

Linked solutions to boundary conformal field theories via nearly marginal deformations.

Modeled creation of lower-dimensional branes during D-brane decay.

Abstract

We discuss a general iterative procedure for constructing time dependent solutions in open string theory describing rolling of a generic tachyon field away from its maximum. These solutions are characterized by two parameters labelling the initial position and velocity of the tachyon field, but one of these parameters can be removed by using time translation symmetry. The Wick rotated version of the resulting one parameter family of inequivalent solutions describes a one parameter family of boundary conformal field theories, each member of which is related to the boundary conformal field theory describing the original D-brane system by a nearly marginal deformation. We apply this technique to construct a time dependent solution on a D-brane in bosonic string theory which can be interpreted as the creation of a lower dimensional brane during the decay of an unstable D-brane.