BRST Invariance of the Non-Perturbative Vacuum in Bosonic Open String Field Theory

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 to satisfy furthermore the requirement of BRST invariance. This is indispensable in order for the theory around the non-perturbative vacuum to be consistent. We carry out the numerical analysis of the BRST invariance of the solution and find that it holds to a good accuracy. We also mention the zero-norm property of the solution. The observations in this paper are expected to give clues to the analytic expression of the vacuum solution.Comment: 14 pages, no figures, LaTeX2e, v2: references added, minor changes, v3: typos correcte

Singularities in K-space and Multi-brane Solutions in Cubic String Field Theory

In a previous paper [arXiv:1111.2389], we studied the multi-brane solutions in cubic string field theory by focusing on the topological nature of the "winding number" N which counts the number of branes. We found that N can be non-trivial owing to the singularity from the zero-eigenvalue of K of the KBc algebra, and that solutions carrying integer N and satisfying the EOM in the strong sense is possible only for N=0,\pm 1. In this paper, we extend the construction of multi-brane solutions to |N|\ge 2. The solutions with N=\pm 2 is made possible by the fact that the correlator is invariant under a transformation exchanging K with 1/K and hence K=\infty eigenvalue plays the same role as K=0. We further propose a method of constructing solutions with |N|\ge 3 by expressing the eigenvalue space of K as a sum of intervals where the construction for |N|\le 2 is applicable.Comment: 20 pages, no figures, v4: version published in JHE

Relativistic Collective Coordinate System of Solitons and Spinning Skyrmion

We consider constructing the relativistic system of collective coordinates of a field theory soliton on the basis of a simple principle: The collective coordinates must be introduced into the static solution in such a way that the equation of motion of the collective coordinates ensures that of the original field theory. As an illustration, we apply this principle to the quantization of spinning motion of the Skyrmion by incorporating the leading relativistic correction to the rigid body approximation. We calculate the decay constant and various static properties of nucleons, and find that the relativistic corrections are in the range of 5% -- 20%. We also examine how the baryons deform due to the spinning motion.Comment: 46 pages, 7 figure

String Junction from Non-Commutative Super Yang-Mills Theory

We construct a 1/4 BPS soliton solution in N=4 non-commutative super Yang-Mills theory to the first order in the non-commutativity parameter \theta_{ij}. We then solve the non-commutative eigenvalue equations for the scalar fields. The Callan-Maldacena interpretation of the eigenvalues precisely reproduces the expected string junction picture: the string junction is tilted against the D3-branes with angle \theta_{ij}.Comment: 19 pages, 6 figures, LaTeX, v3: minor change

Color Confinement in Perturbation Theory from a Topological Model,

Color confinement by the mechanism of Kugo and Ojima can treat confinement of any quantized color carrying fields including dynamical quarks. However, the non-perturbative condition for this confinement has been known to be satisfied only in the pure-gauge model (PGM), which is a topological model without physical degrees of freedom. Here we analyze the Yang-Mills theory by adding physical degrees of freedom as perturbation to PGM. We find that quarks and gluons are indeed confined in this perturbation theory.Comment: 12 pages + 1 uuencoded eps figure, LaTe

Relativistic Collective Coordinate Quantization of Solitons: Spinning Skyrmion

We develop a consistent relativistic generalization of collective coordinate quantization of field theory solitons. Our principle of introducing collective coordinates is that the equations of motion of the collective coordinates ensure those of the original field theory. We illustrate this principle with the quantization of spinning degrees of freedom of Skyrmion representing baryons. We calculate the leading relativistic corrections to the static properties of nucleons, and find that the corrections are non-negligible ones of 10% to 20%.Comment: 6 pages, no figures, REVTeX; appendix added, published in PR

Exact Results on Equations of Motion in Vacuum String Field Theory

We prove some algebraic relations on the translationally invariant solutions and the lump solutions in vacuum string field theory. We show that up to the subtlety at the midpoint the definition of the half-string projectors of the known sliver solution can be generalized to other solutions. We also find that we can embed the translationally invariant solution into the matrix equation of motion with the zero mode.Comment: 12 pages, no figures, LaTeX2e, v2: references adde

String Field Theory in Rindler Space-Time and String Thermalization

Quantization of free string field theory in the Rindler space-time is studied by using the covariant formulation and taking the center-of-mass value of the Rindler string time-coordinate $\eta(\sigma)$ as the time variable for quantization. We construct the string Rindler modes which vanish in either of the Rindler wedges $\pm$ defined by the Minkowski center-of-mass coordinate of the string. We then evaluate the Bogoliubov coefficients between the Rindler string creation/annihilation operators and the Minkowski ones, and analyze the string thermalization. An approach to the construction of the string Rindler modes corresponding to different definitions of the wedges is also presented toward a thorough understanding of the structure of the Hilbert space of the string field theory on the Rindler space-time.Comment: 37 pages + 2 uuencoded eps figures, LaTeX, References adde