Related papers: Fluctuations around the Tachyon Vacuum in Open Str…
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…
We re-examine the recent proposal of Rastelli, Sen and Zwiebach on the tachyon fluctuation of the vacuum string field theory representing a D25 brane, originally considered by Hata and Kawano. We show that the tachyon state satisfies the…
In open string field theory the kinetic operator mixes matter and ghost sectors, and thus the ghost structure of classical solutions is not universal. Nevertheless, we have found from numerical analysis that certain ratios of expectation…
We analyze the consistency of a recently proposed real tachyon vacuum solution without square roots in open bosonic string field theory. We show that the equation of motion contracted with the solution itself is satisfied. Additionally, by…
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…
An outstanding problem in open bosonic string field theory is the existence of nontrivial classical solutions in its universal sector. Such solutions independent of the underlying CFT would be relevant for any background, but aside of the…
We revisit the identity-based solutions for tachyon condensation in open bosonic string field theory (SFT) from the viewpoint of the sine-square deformation (SSD). The string Hamiltonian derived from the simplest solution includes the…
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 discuss a new formula for the symplectic structure on the phase space of open string field theory. Revisiting the setup of Cho, Mazel, and Yin, we use the formula to compute the energy of rolling tachyon solutions on unstable D-branes.…
We give evidence based on level-truncation computations that the rolling tachyon in cubic open string field theory (CSFT) has a well-defined but wildly oscillatory time-dependent solution which goes as $e^t$ for $t \to -\infty$. We show…
We illustrate a method for computing the number of physical states of open string theory at the stable tachyonic vacuum in level truncation approximation. The method is based on the analysis of the gauge-fixed open string field theory…
We evaluate the classical action and the effective tachyon potential of open string field theory within KBc subalgebra, which is extensively used in analytic solution for tachyon condensation recently found by Erler and Schnabl. It is found…
We evaluate gauge invariants, action and gauge invariant overlap, for numerical solutions which satisfy the "a-gauge" condition with various values of $a$ in cubic open bosonic string field theory. We use the level truncation approximation…
We construct the homotopy operators for the BRST operator in the theory around the identity-based solutions, which are believed to represent the tachyon vacuum in cubic bosonic open string field theory. Using the homotopy operators, we find…
We evaluate gauge invariants (vacuum energy and gauge invariant overlap) for numerical classical solutions in cubic open string field theory under Asano-Kato's $a$-gauge fixing condition. We propose an efficient iterative procedure for…
Earlier an analytic approach is proposed for classical solutions describing tachyon vacuum in open string field theory. Based on the approach, we construct a certain class of classical solutions written in terms of holomorphic functions…
We investigate analytic solutions to Witten's bosonic string field theory and Berkovits' WZW-type superstring field theory. We construct solutions with parameters out of simpler ones, using a commutative monoid that includes the family of…
Fluxbrane-like backgrounds obtained from flat space by a sequence of T-dualities and shifts of polar coordinates (beta deformations) provide an interesting class of exactly solvable string theories. We compute the one-loop partition…
We study time dependent solutions in cubic open string field theory which are expected to describe the configuration of the rolling tachyon. We consider the truncated system consisting of component fields of level zero and two, which are…
We study the level-expansion structure of the NS string field theory actions, mainly focusing on the modified (i.e. 0-picture in the NS sector) cubic superstring field theory. This theory has a non-trivial structure already at the quadratic…