26,761 research outputs found
Topological defects in 1D elastic waves
It has been recently shown theoretically that a topological defect in a 1D
periodic potential may give rise to two localized states within the energy
gaps. In this work we present an experimental realization of this effect for
the case of torsional waves in elastic rods. We also show numerically that
three, or even more, localized states can be present if the parameters
characterizing the topological defect are suitably varied.Comment: 3 pages, 4 figures, accepted in Physica
Analytic Non-integrability in String Theory
Using analytic techniques developed for Hamiltonian dynamical systems we show
that a certain classical string configurations in AdS_5 x X_5 with X_5 in a
large class of Einstein spaces, is non-integrable. This answers the question of
integrability of string on such backgrounds in the negative. We consider a
string localized in the center of AdS_5 that winds around two circles in the
manifold X_5.Comment: 14 page
Partition Functions of Pure Spinors
We compute partition functions describing multiplicities and charges of
massless and first massive string states of pure-spinor superstrings in
3,4,6,10 dimensions. At the massless level we find a spin-one gauge multiplet
of minimal supersymmetry in d dimensions. At the first massive string level we
find a massive spin-two multiplet. The result is confirmed by a direct analysis
of the BRST cohomology at ghost number one. The central charges of the pure
spinor systems are derived in a manifestly SO(d) covariant way confirming that
the resulting string theories are critical. A critical string model with
N=(2,0) supersymmetry in d=2 is also described.Comment: LaTex, 30 p
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