12,533 research outputs found
3-Point Functions in N=4 Yang-Mills
Three-point functions of analytic (chiral primary) operators in N=4
Yang-Mills theory in four dimensions are calculated using the harmonic
superspace formulation of this theory. In the case of the energy-momentum
tensor multiplet anomaly considerations determine the coefficient. Analyticity
in N=2 harmonic superspace is explicitly checked in a two-loop calculation.Comment: This file requires the feynman.tex macro Some references are adde
The Six Dimensional Self-Dual Tensor
The equations of motion for a self-interacting self-dual tensor in six
dimensions are extracted from the equations describing the M-theory five-brane.
These equations are presented in a self-contained, six-dimensional
Lorentz-covariant form. In particular, it is shown that the field-strength
tensor satisfies a non-linear generalised self-duality constraint. The
self-duality equation is rewritten in five-dimensional notation and shown to be
identical to the corresponding equation in the non-covariant formalism.Comment: 8 pages, late
Strings and D-Branes with Boundaries
The covariant field equations of ten-dimensional super D-branes are obtained
by considering fundamental strings whose ends lie in the superworldsurface of
the D-brane. By considering in a similar fashion Dp-branes ending on
D(p+2)-branes we derive equations describing D-branes with dual potentials, as
well as the vector potentials.Comment: 12 pages, Late
Aeroplane design study STOL airliner (A71). Part 1- configuration description and data
The interest in STOL airliners was reflected in the
choice of a 100-118 passenger short range aircraft of this
type as the 1971 design project. In addition to the use of
the study for detailed investigation by the students of
Aircraft Design it also served as the basis for an
investigation of the low speed lift and control problems
of STOL aircraft.
This report is concerned with a description of the
configuration adopted and specification of geometric and
aerodynamic data. As such it is the first part of the
complete reporting of the investigation, subsequent parts
being concerned with the more detailed work.
The aircraft was designed to operate from 2000 ft long
single runways and have a cruising speed of up to 11 - 0.83
at 30,000 ft altitude. The estimated gross weight is
115,000 lb and when landing at 100,000 lb weight the approach
speed is 79 knots. The high lift coefficients necessitated
by this are obtained either by externally blown jet flaps or
an augmenter wing arrangement
The supermembrane revisited
The M2-brane is studied from the perspective of superembeddings. We review
the derivation of the M2-brane dynamics and the supergravity constraints from
the standard superembedding constraint and we discuss explicitly the induced
d=3, N=8 superconformal geometry on the worldvolume. We show that the gauged
supermembrane, for a target space with a U(1) isometry, is the standard
D2-brane in a type IIA supergravity background. In particular, the D2-brane
action, complete with the Dirac-Born-Infeld term, arises from the gauged
Wess-Zumino worldvolume 4-form via the brane action principle. The discussion
is extended to the massive D2-brane considered as a gauged supermembrane in a
massive D=11 superspace background. Type IIA supergeometry is derived using
Kaluza-Klein techniques in superspace.Comment: Latex, 46 pages, clarifying remarks and references adde
Explicit construction of nilpotent covariants in N=4 SYM
Some aspects of correlation functions in N=4 SYM are discussed. Using N=4
harmonic superspace we study two and three-point correlation functions which
are of contact type and argue that these contact terms will not affect the
non-renormalisation theorem for such correlators at non-coincident points. We
then present a perturbative calculation of a five-point function at two loops
in N=2 harmonic superspace and verify that it reproduces the derivative of the
previously found four-point function with respect to the coupling. The
calculation of this four-point function via the five-point function turns out
to be significantly simpler than the original direct calculation. This
calculation also provides an explicit construction of an N=2 component of an
N=4 five-point nilpotent covariant that violates U(1)_Y symmetry.Comment: 20 pages, standard late
Open Superbranes
Open branes ending on other branes, which may be referred to as the host
branes, are studied in the superembedding formalism. The open brane, host brane
and the target space in which they are both embedded are all taken to be
supermanifolds. It is shown that the superspace constraints satisfied by the
open brane are sufficient to determine the corresponding superspace constraints
for the host branes, whose dynamics are determined by these constraints. As a
byproduct, one also obtains information about the boundary of the open brane
propagating in the host brane.Comment: 12 pages, late
On Brane Actions and Superembeddings
Actions for branes, with or without worldsurface gauge fields, are discussed
in a unified framework. A simple algorithm is given for constructing the
component Green-Schwarz actions. Superspace actions are also discussed. Three
examples are given to illustrate the general procedure: the membrane in D=11
and the D2-brane, which both have on-shell worldsurface supermultiplets, and
the membrane in D=4, which has an off-shell multiplet.Comment: 19 pages, late
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