17,472 research outputs found
Green-Schwarz Formulation of Self-Dual Superstring
The self-dual superstring has been described previously in a
Neveu-Schwarz-Ramond formulation with local N=2 or 4 world-sheet supersymmetry.
We present a Green-Schwarz-type formulation, with manifest spacetime
supersymmetry.Comment: 11 pg., (uuencoded dvi file) ITP-SB-92-5
Closed String Amplitudes from Gauge Fixed String Field Theory
Closed string diagrams are derived from cubic open string field theory using
a gauge fixed kinetic operator. The basic idea is to use a string propagator
that does not generate a boundary to the world sheet. Using this propagator and
the closed string vertex, the moduli space of closed string surfaces is
covered, so closed string scattering amplitudes should be reproduced. This
kinetic operator could be a gauge fixed form of the string field theory action
around the closed string vacuum.Comment: 10 pages, revtex, 3 figures. Discussion on the covering of moduli
expanded, version to appear in PR
Subcritical Superstrings
We introduce the Liouville mode into the Green-Schwarz superstring. Like
massive supersymmetry without central charges, there is no kappa symmetry.
However, the second-class constraints (and corresponding Wess-Zumino term)
remain, and can be solved by (twisted) chiral superspace in dimensions D=4 and
6. The matter conformal anomaly is c = 4-D < 1. It thus can be canceled for
physical dimensions by the usual Liouville methods, unlike the bosonic string
(for which the consistency condition is c = D <= 1).Comment: 9 pg., compressed postscript file (.ps.Z), other formats (.dvi, .ps,
.ps.Z, 8-bit .tex) available at
http://insti.physics.sunysb.edu/~siegel/preprints/ or at
ftp://max.physics.sunysb.edu/preprints/siege
Invariances and Equations of Motion in Double Field Theory
We investigate the full set of equations of motion in double field theory and
discuss their O(D,D) symmetry and gauge transformation properties. We obtain a
Ricci-like tensor, its associated Bianchi identities, and relate our results to
those with a generalized metric formulation.Comment: 24 page
More Discriminants with the Brezing-Weng Method
The Brezing-Weng method is a general framework to generate families of
pairing-friendly elliptic curves. Here, we introduce an improvement which can
be used to generate more curves with larger discriminants. Apart from the
number of curves this yields, it provides an easy way to avoid endomorphism
rings with small class number
Proximity effect model of ultra-narrow NbN strips
We show that narrow superconducting strips in superconducting (S) and normal
(N) states are universally described by the model presenting them as lateral
NSN proximity systems in which the superconducting central band is sandwiched
between damaged edge-bands with suppressed superconductivity.The width of the
superconducting band was experimentally determined from the value of magnetic
field at which the band transits from the Meissner state to the static vortex
state. Systematic experimental study of 4.9 nm thick NbN strips with widths in
the interval from 50 nm to 20 m, which are all smaller than the Pearl's
length, demonstrates gradual evolution of the temperature dependence of the
critical current with the change of the strip width
Configurations of Handles and the Classification of Divergences in the String Partition Function
The divergences that arise in the regularized partition function for closed
bosonic string theory in flat space lead to three types of perturbation series
expansions, distinguished by their genus dependence. This classification of
infinities can be traced to geometrical characteristics of the string
worldsheet. Some categories of divergences may be eliminated in string theories
formulated on compact manifolds.Comment: 24 pages, DAMTP-R/94/1
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