1,293 research outputs found
Linear relations among 4-point functions in the high energy limit of string theory
The decoupling of zero-norm states leads to linear relations among 4-point
functions in the high energy limit of string theory. Recently it was shown that
the linear relations uniquely determine ratios among 4-point functions at the
leading order. The purpose of this paper is to extend the validity of the same
approach to the next-to-leading order and higher orders.Comment: 17 pages, references added, minor modificatio
Noncommutative D-Brane in Non-Constant NS-NS B Field Background
We show that when the field strength H of the NS-NS B field does not vanish,
the coordinates X and momenta P of an open string endpoints satisfy a set of
mixed commutation relations among themselves. Identifying X and P with the
coordinates and derivatives of the D-brane world volume, we find a new type of
noncommutative spaces which is very different from those associated with a
constant B field background.Comment: 11 pages, Latex, minor modification
High-energy zero-norm states and symmetries of string theory
High-energy limit of zero-norm states (HZNS) in the old covariant first
quantized (OCFQ) spectrum of the 26D open bosonic string, together with the
assumption of a smooth behavior of string theory in this limit, are used to
derive infinitely many linear relations among the leading high-energy, fixed
angle behavior of four point functions of different string states. As a result,
ratios among all high-energy scattering amplitudes of four arbitrary string
states can be calculated algebraically and the leading order amplitudes can be
expressed in terms of that of four tachyons as conjectured by Gross in 1988. A
dual calculation can also be performed and equivalent results are obtained by
taking the high-energy limit of Virasoro constraints. Finally, as a consistent
sample calculation, we compute all high-energy scattering amplitudes of three
tachyons and one massive state at the leading order by saddle-point
approximation to justify our results.Comment: 10 pages, no figure, modifications of text and reference
BPS States on M5-brane in Large C-field Background
We extensively study BPS solutions of the low energy effective theory of
M5-brane in large C-field background. This provides us an opportunity to
explore the interactions turned on by C-field background through the
Nambu-Poisson structure. The BPS states considered in this paper include the
M-waves, the self-dual string (M2 ending on M5), tilted M5-brane, holomorphic
embedding of M5-brane and the intersection of two M5-branes along a 3-brane.Comment: 25 pages, reference adde
Non-Abelian BIonic Brane Intersections
We study "fuzzy funnel" solutions to the non-Abelian equations of motion of
the D-string. Our funnel describes n^6/360 coincident D-strings ending on n^3/6
D7-branes, in terms of a fuzzy six-sphere which expands along the string. We
also provide a dual description of this configuration in terms of the world
volume theory of the D7-branes. Our work makes use of an interesting non-linear
higher dimensional generalization of the instanton equations.Comment: 17 pages uses harvmac; v2: small typos corrected, refs adde
A No-Go Theorem for M5-brane Theory
The BLG model for multiple M2-branes motivates an M5-brane theory with a
novel gauge symmetry defined by the Nambu-Poisson structure. This Nambu-Poisson
gauge symmetry for an M5-brane in large C-field background can be matched, on
double dimension reduction, with the Poisson limit of the noncommutative gauge
symmetry for a D4-brane in B-field background. Naively, one expects that there
should exist a certain deformation of the Nambu-Poisson structure to match with
the full noncommutative gauge symmetry including higher order terms. However,
We prove the no-go theorem that there is no way to deform the Nambu-Poisson
gauge symmetry, even without assuming the existence of a deformation of
Nambu-Poisson bracket, to match with the noncommutative gauge symmetry in 4+1
dimensions to all order, regardless of how the double dimension reduction is
implemented.Comment: v4: minor modifications
Nonlocal Particles as Strings
We find nonlocal particle theories with two dimensional conformal symmetry,
including examples equivalent to the bosonic open string and closed string.
This work provides a new approach to construct solvable consistent backgrounds
in string theory.Comment: 25 pages, Latex, minor change
Matrix Compactification On Orientifolds
Generalizing previous results for orbifolds, in this paper we describe the
compactification of Matrix model on an orientifold which is a quotient space as
a Yang-Mills theory living on a quantum space. The information of the
compactification is encoded in the action of the discrete symmetry group G on
Euclidean space and a projective representation U of G. The choice of Hilbert
space on which the algebra of U is realized as an operator algebra corresponds
to the choice of a physical background for the compactification. All these data
are summarized in the spectral triple of the quantum space.Comment: 28 pages, late
S-brane Actions
We derive effective actions for Spacelike branes (S-branes) and find a
solution describing the formation of fundamental strings in the rolling tachyon
background. The S-brane action is a Dirac-Born-Infeld action for Euclidean
worldvolumes defined in the context of time-dependent tachyon condensation of
non-BPS branes. It includes gauge fields and in particular a scalar field
associated with translation along the time direction. We show that the BIon
spike solutions constructed in this system correspond to the production of a
confined electric flux tube (a fundamental string) at late time of the rolling
tachyon.Comment: 10 pages, 1 figure. References added, typos correcte
Noncommutative Differential Calculus for D-brane in Non-Constant B Field Background
In this paper we try to construct noncommutative Yang-Mills theory for
generic Poisson manifolds. It turns out that the noncommutative differential
calculus defined in an old work is exactly what we need. Using this calculus,
we generalize results about the Seiberg-Witten map, the Dirac-Born-Infeld
action, the matrix model and the open string quantization for constant B field
to non-constant background with H=0.Comment: 21 pages, Latex file, references added, minor modificatio
- …