String field theory solution for any open string background
Abstract
We present an exact solution of open bosonic string field theory which can be used to describe any timeindependent open string background. The solution generalizes an earlier construction of Kiermaier, Okawa, and Soler, and assumes the existence of boundary condition changing operators with nonsingular OPEs and vanishing conformal dimension. Our main observation is that boundary condition changing operators of this kind can describe nearly any open string background provided the background shift is accompanied by a timelike Wilson line of sufficient strength. As an application we analyze the tachyon lump describing the formation of a D$(p1)$brane in the string field theory of a D$p$brane, for generic compactification radius. This not only provides a proof of Sen's second conjecture, but also gives explicit examples of higher energy solutions, confirming analytically that string field theory can "reverse" the direction of the worldsheet RG flow. We also find multiple Dbrane solutions, demonstrating that string field theory can add ChanPaton factors and change the rank of the gauge group. Finally, we show how the solution provides a remarkably simple and nonperturbative proof of the background independence of open bosonic string field theory.
 Publication:

Journal of High Energy Physics
 Pub Date:
 October 2014
 DOI:
 10.1007/JHEP10(2014)029
 arXiv:
 arXiv:1406.3021
 Bibcode:
 2014JHEP...10..029E
 Keywords:

 Tachyon Condensation;
 String Field Theory;
 Conformal Field Models in String Theory;
 Bosonic Strings;
 High Energy Physics  Theory
 EPrint:
 V2: 42 pages, 11 figures, typos corrected