Tachyon Vacuum of Bosonic Open String Field Theory in Marginally Deformed Backgrounds

Understand

We consider bosonic open string field theory in marginally deformed backgrounds, which is obtained by expanding the string field around the identity-based solutions associated with marginal deformations.

• We find a new set of string fields which satisfies the KBc algebra, but the nilpotent kinetic operator is that of the theory expanded around the identity-based marginal solution.
• By use of these string fields, we construct the tachyon vaccum solution in marginally deformed backgrounds.
• The vacuum energy density is equivalent to that of the tachyon vacuum without marginal deformations.