Backreaction and the rolling tachyon—an effective action point of view

Abstract

We compute the decay of an unstable D9 brane in type IIA string theory including backreaction effects using an effective field theory approach. The open string tachyon on the brane is coupled consistently to the space-time metric, the dilaton and the RR 9-form. The purpose of this note is to address the fate of the open string energy density, which remains constant if no interaction with the closed string modes is included. Our computations show that taking only into account the coupling to the massless closed strings the total energy stored in the open string sector vanishes asymptotically, independently how small one chooses g s . We find also the large time behaviour of the fields in the Einstein and string frames. 1

Tachyon Dynamics in Open String Theory

“…Other aspects of closed string field produced by unstable D-branes and other time dependent configurations have been discussed in [69,85,315,285,450,406,534,84,75,407,329,76,119,405,501,452,271,393,267,344,516,32,218,345,305].…”

Particle Production on Half S-Brane

“…This is family of exact solutions of classical 2 For the most recent discussion of S-branes and other time-dependent processes in string theory, see [84,82,81,83,77,79,78,80,85]. 3 We work in units α…”

Closed string field theory with dynamical D-brane

“…By substituting (3.28) into the equations (3.4) and (3.11), we obtain the recursion 11 See also the similar argument based on the low energy effective theory [27] and based on the toy model for open-closed SFT [28,29].…”

“…In fact, as pointed out in [12] the (not covariant) conservation law of the energy momentum tensor of the D-brane, 27) follows from the condition (3.26). This means that the energy exchange between D-brane and the bulk closed strings is completely ignored.…”

“…We only need below is the following properties proved in Ref. [18], 27) where |Φ| represents the Grassmann parity of the closed string field | Φ .…”