Related papers: Numerical solution of open string field theory in …
This short review is based on the lecture given by the author at the Feza G\"ursey Physics Days School 2024. Here we briefly review analytic solutions (in particular, the Erler-Schnabl solution) of open cubic string field theory for the…
In bosonic open string field theory, we construct numerical universal solutions in $a$-gauge corresponding to ``double brane'' and ``ghost brane'' solutions in Siegel gauge in addition to the tachyon vacuum solution, and evaluate their…
We reexamine the oscillator construction of the D25-brane solution and the tachyon fluctuation mode of vacuum string field theory given previously. Both the classical solution and the tachyon mode are found to violate infinitesimally their…
Tachyon condensation on a bosonic D-brane was recently demonstrated numerically in Witten's open string field theory with level truncation approximation. This non-perturbative vacuum, which is obtained by solving the equation of motion, has…
In bosonic open string field theory, the spectrum around the numerical tachyon vacuum solution in Siegel gauge was investigated by Giusto and Imbimbo. Using their numerical method, we study the mass spectrum around two other solutions,…
We investigate the string field theory around the tachyon vacuum. A pure gauge form of the solution is constructed at the tachyon vacuum. For a special choice of the gauge function for the pure gauge form, marginal deformation from the…
The level truncation approach to string field theory is used to study the zero-momentum action for vector excitations on a bosonic D-brane which has been annihilated by tachyon condensation. It is shown that in the true vacuum the…
We compute the tachyon potential to level 4 in NS superstring field theory. We obtain 89% of the conjectured vacuum energy.
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…
We argue that the closed string energy in the bulk bouncing tachyon background is to be quantised in a simple manner as if strings were trapped in a finite time interval. We discuss it from three different viewpoints; (1) the timelike…
We study some properties of the tachyonic lumps in the level truncation scheme of bosonic cubic string field theory. We find that several gauges work well and that the size of the lump as well as its tension is approximately independent of…
A gauge invariant action for the open bosonic string has been proposed in an earlier paper. We work out the consequences of this proposal for the lowest mode, viz. the tachyon. The action can be calculated for generic momenta,…
We calculate gauge invariant observables for Schnabl's solution with analytic method and with the level truncation approximation. We also compute them for the numerical solution initially obtained by Sen and Zwiebach in the level truncation…
We use level truncated superstring field theory to obtain the effective potential for the Wilson line marginal deformation parameter which corresponds to the constant vacuum expectation value of the U(1) gauge field on the D-brane in a…
It has been conjectured that at the stationary point of the tachyon potential for the non-BPS D-brane or brane-anti-D-brane pair, the negative energy density cancels the brane tension. We study this conjecture using a cubic superstring…
We use open string field theory to study the dynamics of unstable branes in the bosonic string theory, in the background of a generic linear dilaton. We find a simple exact solution describing a dynamical interpolation between the…
We discuss the convergence of level truncation in bosonic open string field theory. As a test case we consider the calculation of the quartic tachyon coupling $\gamma_4$. We determine the exact contribution from states up to level L=28 and…
We use the level truncation scheme to obtain accurate descriptions of open bosonic string field configurations corresponding to large marginal deformations such as background Wilson lines. To do so, we solve for all fields as functions of…
In these notes we revisit the tachyon lagrangian in the open string field theory using background independent approach of Witten from 1992. We claim that the tree level lagrangian (up to second order in derivatives and modulo some class of…
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…