A Solvable Toy Model for Tachyon Condensation in String Field Theory
نویسنده
چکیده
The lump solution of φ field theory provides a toy model for unstable D-branes of bosonic string theory. The field theory living on this lump is itself a cubic field theory involving a tachyon, two additional scalar fields, and a scalar field continuum. Its action can be written explicitly because the fluctuation spectrum of the lump turns out to be governed by a solvable Schroedinger equation; the l = 3 case of a series of reflectionless potentials. We study the multiscalar tachyon potential both exactly and in the level expansion, obtaining insight into issues of convergence, branches of the solution space, and the mechanism for removal of states after condensation. In particular we find an interpretation for the puzzling finite domain of definition of string field marginal parameters. E-mail: [email protected]
منابع مشابه
Tachyon condensation on brane sphalerons
We consider a sphaleron solution in field theory that provides a toy model for unstable D-branes of string theory. We investigate the tachyon condensation on a Dp-brane. The localized modes, including a tachyon, arise in the spectrum of a sphaleron solution of a φ4 field theory on M p+1 × S1. We use these modes to find a multiscalar tachyon potential living on the sphaleron world-volume. A comp...
متن کاملLectures on D - branes , tachyon condensation , and string field theory
These lectures provide an introduction to the subject of tachyon condensation in the open bosonic string. The problem of tachyon condensation is first described in the context of the low-energy Yang-Mills description of a system of multiple D-branes, and then using the language of string field theory. An introduction is given to Witten's cubic open bosonic string field theory. The Sen conjectur...
متن کاملWorldsheet Description of Tachyon Condensation in Open String Theory
In this thesis we review the fundamental framework of boundary string field theory (BSFT) and apply it to the tachyon condensation on non-BPS systems in the superstring theory. The boundary string field theory can be regarded as a natural extension of the nonlinear sigma model. By using this theory we can describe the tachyon condensation exactly and also obtain the effective actions on non-BPS...
متن کاملA Review on Tachyon Condensation in Open String Field Theories
We review the recent studies of tachyon condensation in string field theory. After introducing the open string field theory both for bosonic string and for superstring, we use them to examine the conjecture that the unstable configurations of the D-brane will decay into the ‘closed string vacuum’ through the tachyon condensation. And we describe the attemps to construct a lower dimensional boso...
متن کاملTachyon Condensation in Large Magnetic Fields with Background Independent String Field Theory
We discuss the problem of tachyon condensation in the framework of background independent open string field theory. We show, in particular, that the computation of the string field theory action simplifies considerably if one looks at closed string backgrounds with a large Bab field, and can be carried out exactly for a generic tachyon profile. We confirm previous results on the form of the exa...
متن کامل