96 research outputs found
Gravitational Dielectric Effect and Myers Effect
In this paper we study the gravitational dielectric phenomena of a D2-brane
in the background of Kaluza-Klein monopoles and D6-branes. In both cases the
spherical D2-brane with nonzero radius becomes classical solution of the
D2-brane action. We also investigate the gravitational Myers effect in the
background of D6-branes. This phenomenon occurs since the tension of the
D2-brane balances with the repulsive force between D0-branes and D6-branes.Comment: 17 pages, 4 figures, The argument on the stability of the spehrical
D2-D0 bound state is modified and clarified in the appendix, The effect of
background R-R field are included, reference added, version appeared in PR
Higher Derivative Corrections to Eleven Dimensional Supergravity via Local Supersymmetry
In this paper we derive higher derivative corrections to the eleven
dimensional supergravity by applying the Noether method with respect to the N=1
local supersymmetry. An ansatz for the higher derivative effective action,
which includes quartic terms of the Riemann tensor, is parametrized by 132
parameters. Then we show that by the requirement of the local supersymmetry,
the higher derivative effective action is essentially described by two
parameters. The bosonic parts of these two superinvariants completely match
with the known results obtained by the perturbative calculations in the type
IIA superstring theory. Since the calculations are long and systematic, we
build the computer programming to check the cancellation of the variations
under the local supersymmetry. This is an extended version of our previous
paper hep-th/0508204.Comment: 67 pages, no figure, references added, typos correcte
Field Theory Supertubes
Starting with intersecting M2-branes in M-theory, the IIA supertube can be
found by compactification with a boost to the speed of light in the compact
dimension. A similar procedure applied to Donaldson-Uhlenbeck-Yau instantons on
\bC^3, viewed as intersecting membranes of 7D supersymmetric Yang-Mills (SYM)
theory, yields (for finite boost) a new set of 1/4 BPS equations for 6D
SYM-Higgs theory, and (for infinite boost) a generalization of the dyonic
instanton equations of 5D SYM-Higgs theory, solutions of which are interpreted
as Yang-Mills supertubes and realized as configurations of IIB string theory.Comment: 11 pages. Contribution to Strings '04. Revised to include minor
corrections and additional reference
Anomalies and O-plane charges in orientifolded brane tilings
We investigate orientifold of brane tilings. We clarify how the cancellations
of gauge anomaly and Witten's anomaly are guaranteed by the conservation of the
D5-brane charge. We also discuss the relation between brane tilings and the
dual Calabi-Yau cones realized as the moduli spaces of gauge theories. Two
types of flavor D5-branes in brane tilings and corresponding superpotentials of
fundamental quark fields are proposed, and it is shown that the massless loci
of these quarks in the moduli space correctly reproduce the worldvolume of
flavor D7-branes in the Calabi-Yau cone dual to the fivebrane system.Comment: 46 pages, 19 figure
The Exchange of Orientifold Two-Planes in M-theory
We propose an M-theory lift picture of the exchange among type IIA
orientifold two-planes. This consists in wrapping a M5-brane on a three-cycle
in the transverse space of the M-theory orientifold plane OM2. A flux
quantization condition for the three-form self-dual field strength, on the
worldvolume of the M5-brane is computed. This condition establishes the value
which explains the relative charge between two different OM2-planes. Also, we
find that the exchange of the four types of orientifold two-planes in string
theory, has a common picture in M-theory. Moreover, we find that the assignment
of the extra charge is fixed by cohomology and by the flux quantization of the
field strength G in M-theory. We conclude that cohomology is sufficient to
describe some orientifold properties in M-theory, that at string theory level,
only K-theory is able to explain.Comment: 23+1 pages, 6 figures. v2: typos corrected, references adde
Relating branes and matrices
We construct a general map between a Dp-brane with magnetic flux and a matrix
configuration of D0-branes, by showing how one can rewrite the boundary state
of the Dp-brane in terms of its D0-brane constituents. This map gives a simple
prescription for constructing the matrices of fuzzy spaces corresponding to
branes of arbitrary shape and topology. Since we explicitly identify the
D0-brane degrees of freedom on the brane, we also derive the D0-brane charge of
the brane in a very direct way including the A-genus term. As a check on our
formalism, we use our map to derive the abelian-Born-Infeld equations of motion
from the action of the D0-brane matrices.Comment: 28 pages, Late
Generally Covariant Actions for Multiple D-branes
We develop a formalism that allows us to write actions for multiple D-branes
with manifest general covariance. While the matrix coordinates of the D-branes
have a complicated transformation law under coordinate transformations, we find
that these may be promoted to (redundant) matrix fields on the transverse space
with a simple covariant transformation law. Using these fields, we define a
covariant distribution function (a matrix generalization of the delta function
which describes the location of a single brane). The final actions take the
form of an integral over the curved space of a scalar single-trace action built
from the covariant matrix fields, tensors involving the metric, and the
covariant distribution function. For diagonal matrices, the integral localizes
to the positions of the individual branes, giving N copies of the single-brane
action.Comment: 34 pages, LaTeX. v2: comments and refs adde
Fuzzy Sphere Dynamics and Non-Abelian DBI in Curved Backgrounds
We consider the non-Abelian action for the dynamics of -branes in the
background of -branes, which parameterises a fuzzy sphere using the SU(2)
algebra. We find that the curved background leads to collapsing solutions for
the fuzzy sphere except when we have branes in the background, which
is a realisation of the gravitational Myers effect. Furthermore we find the
equations of motion in the Abelian and non-Abelian theories are identical in
the large limit. By picking a specific ansatz we find that we can
incorporate angular momentum into the action, although this imposes restriction
upon the dimensionality of the background solutions. We also consider the case
of non-Abelian non-BPS branes, and examine the resultant dynamics using
world-volume symmetry transformations. We find that the fuzzy sphere always
collapses but the solutions are sensitive to the combination of the two
conserved charges and we can find expanding solutions with turning points. We
go on to consider the coincident 5-brane background, and again construct
the non-Abelian theory for both BPS and non-BPS branes. In the latter case we
must use symmetry arguments to find additional conserved charges on the
world-volumes to solve the equations of motion. We find that in the Non-BPS
case there is a turning solution for specific regions of the tachyon and radion
fields. Finally we investigate the more general dynamics of fuzzy
in the -brane background, and find collapsing solutions
in all cases.Comment: 49 pages, 3 figures, Latex; Version to appear in JHE
Comments on orientifold projection in the conifold and SO x USp duality cascade
We study the O3-plane in the conifold. On the D3-brane world-volume we obtain
SO x USp gauge theory that exhibits a duality cascade phenomenon. The
orientifold projection is determined on the type IIB string side, and
corresponds to that of O4-plane on the dual type IIA side. We show that SUGRA
solutions of Klebanov-Tseytlin and Klebanov-Strassler survive under the
projection. We also investigate the orientifold projection in the generalized
conifolds, and verify desired features of the O4-projection in the type IIA
picture.Comment: 1+27 pages, 9 figures, references added; version to appear in Phys.
Rev.
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