Related papers: BRS Invariance of Unoriented Open-Closed String Fi…
The string field theory for unoriented open-closed string mixed system is constructed up to quadratic order based on the joining-splitting type vertices. The gauge invariance with closed string transformation parameter is proved. The…
We investigate a classical open-closed string field theory whose open string sector is given by boundary string field theory. The open-closed interaction is introduced by the overlap of a boundary state with a closed string field. With the…
In this paper, we study open-closed string field theory in the background B-field in the so-called alpha=p^{+} formulation. The string field theory in the infrared gives noncommutative gauge theory in the open string sector. Since this…
We study gauge invariant operators of open string field theory and find a precise correspondence with on-shell closed strings. We provide a detailed proof of the gauge invariance of the operators and a heuristic interpretation of their…
We construct Lorentz invariant and gauge invariant 1PI effective action for closed and open superstrings and demonstrate that it satisfies the classical BV master equation. We also construct the quantum master action for this theory…
We study a $U(N)$-invariant vector+matrix chain with the color structure of a lattice gauge theory with quarks and interpret it as a theory of open andclosed strings with target space $\Z$. The string field theory is constructed as a…
We discuss the construction of boundary contributions to free string field theory actions in the context of the bosonic string. We show that it is generally possible to obtain a well-defined variational principle by adding a simple boundary…
We use the BSFT method to study the unoriented open string field theory (type I). The partition function on the Mobius strip is calculated. We find that, at the one-loop level, the divergence coming from planar graph and unoriented graph…
We construct a class of BRST-invariant closed string states for any classical solution of open string field theory. The closed string state is a nonlinear functional of the open string field and changes by a BRST-exact term under a gauge…
An exact renormalization group equation is written down for the world sheet theory describing the bosonic open string in general backgrounds. Loop variable techniques are used to make the equation gauge invariant. This is worked out…
In this review we describe our current understanding of the properties of open string tachyons on an unstable D-brane or brane-antibrane system in string theory. The various string theoretic methods used for this study include techniques of…
We formulate a string field theory for open $\mathcal{N}=2$ strings with an $A_{\infty}$ algebra structure. Starting from the BRST cohomology relative to the U(1) anti-ghost zero-mode, we generalize [arXiv:1312.2948] and constructed all…
We study gauge invariant quantities in the open superstring field theory proposed by Berkovits, extending the precedent discussion in bosonic string field theory. Our gauge invariants are ``on-shell''. As its applications, we define…
We show that the boundary states are idempotent B*B=B with respect to the star product of HIKKO type closed string field theory. Variations around the boundary state correctly reproduce the open string spectrum with the gauge symmetry. We…
We study covariant open bosonic string field theories on multiple $Dp$-branes by using the deformed cubic string field theory which is equivalent to the string field theory in the proper-time gauge. Constructing the Fock space…
We extend an earlier proposal for a gauge invariant description of off-shell open strings (at tree level), using loop variables, to off-shell closed strings (at tree level). The basic idea is to describe the closed string amplitudes as a…
We consider a closed string field theory with an arbitrary matter current as a source of the closed string field. We find that the source must satisfy a constraint equation as a consequence of the BRST invariance of the theory. We see that…
We construct a system of bosonic closed string field theory coupled to a D-brane. The interaction between the D-brane and closed string field is introduced using the boundary state which is a function of constant field strength $F_{\mu\nu}$…
The multiloop amplitudes for open bosonic string in presence of a constant B-field are derived from first principles. The basic ingredients of the construction are the commutation relations for the string modes and the Reggeon vertex…
To study noncommutativity properties of the open string with constant B-field we construct a mechanical action which reproduces classical dynamics of the string sector under consideration. It allows one to apply the Dirac quantization…