306 research outputs found
Strings in plane wave backgrounds
I review aspects of string theory on plane wave backgrounds emphasising the
connection to gauge theory given by the BMN correspondence. Topics covered
include the Penrose limit and its role in deriving the BMN duality from
AdS/CFT, light-cone string field theory in the maximally supersymmetric plane
wave and extensions of the correspondence to less supersymmetric backgrounds.Comment: 85 pages, based on PhD thesis, Humboldt University, Berlin; v2: added
reference
PP-Wave Light-Cone Superstring Field Theory
We construct the cubic interaction vertex and dynamically generated
supercharges in light-cone superstring field theory in the pp-wave background.
We show that these satisfy the pp-wave superalgebra at first order in string
coupling. The cubic interaction vertex and dynamical supercharges presented
here differ from the expressions previously given in the literature. Using this
vertex we compute various string theory three-point functions and comment on
their relation to gauge theory in the BMN limit.Comment: 32 pages, 1 figure; v2: typos corrected, reference adde
On the Uniqueness of Plane-wave String Field Theory
We prove that the two interaction Hamiltonians of light-cone closed
superstring field theory in the plane-wave background present in the literature
are identical.Comment: 15 pages late
Low Energy Action of "Covariant" Superstring Field Theory in the NS-NS pp-Wave Background
Exact construction of superstring field theory in some background fields is
very important. We construct the low energy NS-NS sector of superstring field
action in the pp-wave background with the flux of NS-NS antisymmetric tensor
field (NS-NS pp-wave) without gauge fixing up to the second-order where the
action is world-sheet BRST invariant. Here we use the word "covariant" in a
invariant theory for a symmetric transformation of the pp-wave background which
is not the Lorentz transformation in the flat background. Moreover we prove the
exact correspondence between this low energy action and the second-order
perturbation of supergravity action in the same background. We also prove the
correspondence of the gauge transformation in both the actions. This
construction is based on the BRST first quantization of superstrings in the
pp-wave background in our previous paper.Comment: 34 page
The in-situ cometary particulate size distribution measured for one comet: P/Halley
The close approach of Giotto to comet Halley during its 1986 apparition offered an opportunity to study the particulate mass distribution to masses of up to one gram. Data acquired by the front end channels of the highly sensitive mass spectrometer PIA and the dust shield detector system, DIDSY, provide definition to the detected distribution as close as 1000 km to the nucleus. Dynamic motion of the particulates after emission leads to a spatial differentiation affecting the size distribution in several forms: (1) ejecta velocity dispersion; (2) radiation pressure; (3) varying heliocentric distance; and (4) anisotropic nucleus emission. Transformation of the in-situ distribution from PIA and DIDSY weighted heavily by the near-nucleus fluxes leads to a presumed nucleus distribution. The data lead to a puzzling distribution at large masses, not readily explained in an otherwise monotonous power law distribution. Although temporal changes in nucleus activity could and do modify the in-situ size distribution, such an explanation is not wholly possible, because the same form is observed at differing locations in the coma where the time of flight from the nucleus greatly varies. Thus neither a general change in comet activity nor spatial variations lead to a satisfactory explanation
Strong Evidence In Favor OF The Existence Of S-Matrix For Strings In Plane Waves
Field theories on the plane wave background are considered. We discuss that
for such field theories one can only form 1+1 dimensional freely propagating
wave packets. We analyze tree level four point functions of scalar field theory
as well as scalars coupled to gauge fields in detail and show that these four
point functions are well-behaved so that they can be interpreted as S-matrix
elements for 2 particle 2 particle scattering amplitudes. Therefore, at
least classically, field theories on the plane wave background have S-matrix
formulation.Comment: Latex file, 26 pages, 4 eps figures. v3: In the end of paper there is
a "Note Added" as an update of the result
A Representation of Symmetry Generators for the Type IIB Superstring on a Plane Wave in the U(4) Formalism
We calculate the symmetry currents for the type IIB superstring on a
maximally supersymmetric plane wave background using the N=(2,2)
superconformally covariant U(4) formulation developed by Berkovits, Maldacena
and Maoz. An explicit realization of the U(4) generators together with 16
fermionic generators is obtained in terms of the N=(2,2) worldsheet fields.
Because the action is no longer quadratic, we use a light-cone version to
display the currents in terms of the covariant worldsheet variables.Comment: 9 pages, harvmac, Corrected some typographical errors, Added
reference
Cubic couplings in D=6, N=4b supergravity on AdS3×S3
We determine the AdS exchange diagrams needed for the computation of 4-point functions of chiral primary operators in the SCFT2 dual to the D=6, N=4b supergravity on the AdS3×S3 background and compute the corresponding cubic couplings. We also address the issue of consistent truncation
Graviton-Scalar Interaction in the PP-Wave Background
We compute the graviton two scalar off-shell interaction vertex at tree level
in Type IIB superstring theory on the pp-wave background using the light-cone
string field theory formalism. We then show that the tree level vertex vanishes
when all particles are on-shell and conservation of p_{+} and p_{-} are
imposed. We reinforce our claim by calculating the same vertex starting from
the corresponding SUGRA action expanded around the pp-wave background in the
light-cone gauge.Comment: 26 pages, harvmac One reference added. A few comments changed in the
introduction. The "cyclic perms." term removed from some equations as
unnecessary and equations (2.38) and (3.19) are corrected accordingl
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