49 research outputs found
Yang-Mills Action from Open Superstring Field Theory
We calculate the effective action for nonabelian gauge bosons up to quartic
order using WZW-like open superstring field theory. After including level zero
and level one contributions, we obtain with 75% accuracy the Yang-Mills quartic
term. We then prove that the complete effective action reproduces the exact
Yang-Mills quartic term by analytically performing a summation over the
intermediate massive states.Comment: 10 page
Exotic Universal Solutions in Cubic Superstring Field Theory
We present a class of analytic solutions of cubic superstring field theory in
the universal sector on a non-BPS D-brane. Computation of the action and gauge
invariant overlap reveal that the solutions carry half the tension of a non-BPS
D-brane. However, the solutions do not satisfy the reality condition. In fact,
they display an intriguing topological structure: We find evidence that
conjugation of the solutions is equivalent to a gauge transformation that
cannot be continuously deformed to the identity.Comment: 53 pages, 6 figures. Added appendix on splitting charges and midpoint
insertions. Improved presentation of the topological structure of the
solutions. Version accepted at JHE
Open String Amplitudes in Various Gauges
Recently, Schnabl constructed the analytic solution of the open string
tachyon. Subsequently, the absence of the physical states at the vacuum was
proved. The development relies heavily on the use of the gauge condition
different from the ordinary one. It was shown that the choice of gauge
simplifies the analysis drastically. When we perform the calculation of the
amplitudes in Schnabl gauge, we find that the off-shell amplitudes of the
Schnabl gauge is still very complicated. In this paper, we propose the use of
the propagator in the modified Schnabl gauge and show that this modified use of
the Schnabl gauge simplifies the computation of the off-shell amplitudes
drastically. We also compute the amplitudes of open superstring in this gauge.Comment: 23 pages, minor correction
Tachyon Vacuum in Cubic Superstring Field Theory
In this paper we give an exact analytic solution for tachyon condensation in
the modified (picture 0) cubic superstring field theory. We prove the absence
of cohomology and, crucially, reproduce the correct value for the D-brane
tension. The solution is surprising for two reasons: First, the existence of a
tachyon vacuum in this theory has not been definitively established in the
level expansion. Second, the solution {\it vanishes} in the GSO sector,
implying a ``tachyon vacuum'' solution exists even for a {\it BPS} D-brane.Comment: 16 pages, 2 figure
Superstring field theory equivalence: Ramond sector
We prove that the finite gauge transformation of the Ramond sector of the
modified cubic superstring field theory is ill-defined due to collisions of
picture changing operators.
Despite this problem we study to what extent could a bijective classical
correspondence between this theory and the (presumably consistent)
non-polynomial theory exist. We find that the classical equivalence between
these two theories can almost be extended to the Ramond sector: We construct
mappings between the string fields (NS and Ramond, including Chan-Paton factors
and the various GSO sectors) of the two theories that send solutions to
solutions in a way that respects the linearized gauge symmetries in both sides
and keeps the action of the solutions invariant. The perturbative spectrum
around equivalent solutions is also isomorphic.
The problem with the cubic theory implies that the correspondence of the
linearized gauge symmetries cannot be extended to a correspondence of the
finite gauge symmetries. Hence, our equivalence is only formal, since it
relates a consistent theory to an inconsistent one. Nonetheless, we believe
that the fact that the equivalence formally works suggests that a consistent
modification of the cubic theory exists. We construct a theory that can be
considered as a first step towards a consistent RNS cubic theory.Comment: v1: 24 pages. v2: 27 pages, significant modifications of the
presentation, new section, typos corrected, references adde
Rolling to the tachyon vacuum in string field theory
We argue that the rolling-tachyon solution in cubic OSFT proceeds at late
times to precisely the analytic tachyon-vacuum solution constructed by Schnabl.
In addition, we demonstrate the relationship between the rolling-tachyon
solution and the standard BCFT description by showing that there is a finite
gauge transformation which relates the two.Comment: 16 pages, 5 figures, References and comments adde
Solitons on compact and noncompact spaces in large noncommutativity
We study solutions at the minima of scalar field potentials for Moyal spaces
and torii in the large non-commutativity and interprete these solitons in terms
of non-BPS D-branes of string theory. We derive a mass spectrum formula linking
different D-branes together on quantum torii and suggest that it describes
general systems of D-brane bound states extending the D2-D0 one. Then we
propose a shape for the effective potential approaching these quasi-stable
bound states. We give the gauge symmetries of these systems of branes and show
that they depend on the quantum torii representations.Comment: 25 pages, Latex, 1 figure (use epsfig.sty), corrected formul
Validity of Gauge-Fixing Conditions and the Structure of Propagators in Open Superstring Field Theory
We make a detailed analysis on validity of gauge-fixing conditions and the
structure of propagators in the Wess-Zumino-Witten-type open superstring field
theory. First, we generalize the gauge-fixing conditions considered in JHEP 03
(2012) 030 [arXiv:1201.1761] by the present author et al., and propose a large
class of conditions characterized by zero modes of world-sheet oscillators.
Then we demonstrate its validity: we prove that gauge degrees of freedom allow
us to impose the conditions, and that the conditions fix the gauges completely.
Moreover, we elucidate how the information about the gauge choices is reflected
in the structure of propagators. The results can be readily extended to the
case in which gauge-fixing conditions involve linear combinations of the
world-sheet oscillators, including nonzero modes. We investigate also such
extended gauges, which are the counterpart of linear -gauges in bosonic
string field theory, and obtain the corresponding propagators.Comment: LaTeX2e, 79 pages, 2 figures; v2: 80 pages, typos corrected, minor
changes; v3: Footnotes 15 and 16, and a few sentences have been added in
order to clarify the argument. typos corrected, published in JHEP; v4: typos
in equation (6.76) correcte
Open superstring field theory I: gauge fixing, ghost structure, and propagator
The WZW form of open superstring field theory has linearized gauge invariances associated with the BRST operator Q and the zero mode η [subscript 0] of the picture minus-one fermionic superconformal ghost. We discuss gauge fixing of the free theory in a simple class of gauges using the Faddeev-Popov method. We find that the world-sheet ghost number of ghost and antighost string fields ranges over all integers, except one, and at any fixed ghost number, only a finite number of picture numbers appear. We calculate the propagators in a variety of gauges and determine the field-antifield content and the free master action in the Batalin-Vilkovisky formalism. Unlike the case of bosonic string field theory, the resulting master action is not simply related to the original gauge-invariant action by relaxing the constraint on the ghost and picture numbers.United States. Dept. of Energy (Cooperative rRsearch Agreement DE-FG02-05ER41360.
Comments on regularization of identity based solutions in string field theory
We analyze the consistency of the recently proposed regularization of an
identity based solution in open bosonic string field theory. We show that the
equation of motion is satisfied when it is contracted with the regularized
solution itself. Additionally, we propose a similar regularization of an
identity based solution in the modified cubic superstring field theory.Comment: 24 pages, two subsections added, two references adde