1,456 research outputs found
Eleven-Dimensional Supergravity in Light-Cone Superspace
We show that Supergravity in eleven dimensions can be described in terms of a
constrained superfield on the light-cone, without the use of auxiliary fields.
We build its action to first order in the gravitational coupling constant
\kappa, by "oxidizing" (N=8,d=4) Supergravity. This is simply achieved, as for
N=4 Yang-Mills, by extending the transverse derivatives into superspace. The
eleven-dimensional SuperPoincare algebra is constructed and a fourth order
interaction is conjectured.Comment: 18 page
LC_2 formulation of supergravity
We formulate (N=1, d=11) supergravity in components in light-cone gauge
(LC_2) to order . In this formulation, we use judicious gauge choices
and the associated constraint relations to express the metric, three-form and
gravitino entirely in terms of the physical degrees of freedom in the theory.Comment: 11 page
Supersymmetric Yang-Mills theories:not quite the usual perspectivespective
In this paper, we take up an old thread of development concerning the characterization of supersymmetric theories without any use of anticommuting variables that goes back to one of the authors' very early work [1]. Our special focus here will be on the formulation of supersymmetric Yang-Mills theories, extending previous results beyond dimensions. This perspective is likely to provide new insights into these theories, and in particular the maximally extended theory. As a new result we present a novel derivation of the admissible dimensions for interacting (pure) super-Yang-Mills theories to exist. This article is dedicated to the memory of Peter Freund, amongst many other things an early contributor to supersymmetry, and an author of one of the very first papers on superconformal gauge theories [2]. The final section contains some personal reminiscences of H.N.'s encounters with Peter Freund
Electron transport properties of sub-3-nm diameter copper nanowires
Density functional theory and density functional tight-binding are applied to
model electron transport in copper nanowires of approximately 1 nm and 3 nm
diameters with varying crystal orientation and surface termination. The copper
nanowires studied are found to be metallic irrespective of diameter, crystal
orientation and/or surface termination. Electron transmission is highly
dependent on crystal orientation and surface termination. Nanowires oriented
along the [110] crystallographic axis consistently exhibit the highest electron
transmission while surface oxidized nanowires show significantly reduced
electron transmission compared to unterminated nanowires. Transmission per unit
area is calculated in each case, for a given crystal orientation we find that
this value decreases with diameter for unterminated nanowires but is largely
unaffected by diameter in surface oxidized nanowires for the size regime
considered. Transmission pathway plots show that transmission is larger at the
surface of unterminated nanowires than inside the nanowire and that
transmission at the nanowire surface is significantly reduced by surface
oxidation. Finally, we present a simple model which explains the transport per
unit area dependence on diameter based on transmission pathways results
Supersymmetric Yang-Mills theory in D=6 without anti-commuting variables
Supersymmetric Yang-Mills theory is formulated in six dimensions, without the use of anti-commuting variables. This is achieved using a new Nicolai map, to third order in the coupling constant. This is the second such map in six dimensions and highlights a potential ambiguity in the formalism
A personal-computer-based imaging Stokes polarimeter for solar observations
For measurements of vector magnetic field over solar active regions, a Stokes polarimeter for studying the polarisation profiles on selected spectral lines is described. This paper gives details of the relevant CCD imaging system and the personal computer (PC)-based acquisition, together with the image analysis techniques necessary for the task. Field trials and tests of the system are also described
Myth and the creative process: A view of creativity in the light of three Indian myths(NIAS Lecture L1 - 2004)
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