5,811 research outputs found
Conformal Moduli and b-c Pictures for NSR Strings
We explore the geometry of the superconformal moduli of the NSR superstring
theory in order to construct the consistent sigma-model for the NSR strings,
free of picture-changing ambiguities. The sigma-model generating functional is
constructed by the integration over the bosonic and anticommuting moduli,
corresponding to insertions of the vertex operators in scattering amplitudes.
In particular, the integration over the bosonic moduli results in the
appearance of picture-changing operators for the b-c system. Important example
of the b-c pictures involves the unintegrated and integrated forms of the
vertex operators. We derive the BRST-invariant expressions for the b-c
picture-changing operators for open and closed strings and study some of their
properties. We also show that the superconformal moduli spaces of the NSR
superstring theory contain the global singularities, leading to the appearance
of non-perturbative solitonic D-brane creation operators.Comment: 22 pages, references adde
CO(J=6-5) Observations of the Quasar SDSS1044-0125 at z = 5.8
We present a result of the quasar CO(J=6-5) observations of SDSSp
J104433.04-012502.2 at z = 5.8. Ten-days observations with the Nobeyama
Millimeter Array yielded an rms noise level of ~ 2.1 mJy/beam in a frequency
range from 101.28 GHz to 101.99 GHz at a velocity resolution of 120 km/s. No
significant clear emission line was detected in the observed field and
frequency range. Three sigma upper limit on the CO(J=6-5) luminosity of the
object is 2.8 x 10^10 K km/s pc^2, corresponding to a molecular gas mass of 1.2
x 10^11 Solar Mass, if a conversion factor of 4.5 Solar Mass /(K km/s pc^2) is
adopted. The obtained upper limit on CO luminosity is slightly smaller than
those observed in quasars at z=4-5 toward which CO emissions are detected.Comment: 4 pages, 3 figures, LaTeX2e, to appear in Publication of Astronomical
Society of Japan (PASJ), Postscript file available at
ftp://ftp.kusastro.kyoto-u.ac.jp/pub/iwata/preprint/sdss1044/sdss.ps.g
Intersecting black branes in strong gravitational waves
We consider intersecting black branes with strong gravitational waves
propagating along their worldvolume in the context of supergravity theories.
Both near-horizon and space-filling gravitational wave modes are included in
our ansatz. The equations of motion (originally, partial differential
equations) are shown to reduce to ordinary differential equations, which
include a Toda-like system. For special arrangements of intersecting black
branes, the Toda-like system becomes integrable, permitting a more thorough
analysis of the gravitational equations of motion.Comment: 17 pages; v2: cosmetic improvements, published versio
Screening of a hypercritical charge in graphene
Screening of a large external charge in graphene is studied. The charge is
assumed to be displaced away or smeared over a finite region of the graphene
plane. The initial decay of the screened potential with distance is shown to
follow the 3/2 power. It gradually changes to the Coulomb law outside of a
hypercritical core whose radius is proportional to the external charge.Comment: (v1) 4 pages, 1 figure (v2) Much improved introduction; extended
range of numeric
Self-replication and splitting of domain patterns in reaction-diffusion systems with fast inhibitor
An asymptotic equation of motion for the pattern interface in the
domain-forming reaction-diffusion systems is derived. The free boundary problem
is reduced to the universal equation of non-local contour dynamics in two
dimensions in the parameter region where a pattern is not far from the points
of the transverse instabilities of its walls. The contour dynamics is studied
numerically for the reaction-diffusion system of the FitzHugh-Nagumo type. It
is shown that in the asymptotic limit the transverse instability of the
localized domains leads to their splitting and formation of the multidomain
pattern rather than fingering and formation of the labyrinthine pattern.Comment: 9 pages (ReVTeX), 5 figures (postscript). To be published in Phys.
Rev.
Metal-nonmetal transition in LixCoO2 thin film and thermopower enhancement at high Li concentration
We investigate the transport properties of LixCoO2 thin films whose
resistivities are nearly an order of magnitude lower than those of the bulk
polycrystals. A metal-nonmetal transition occurs at ~0.8 in a biphasic domain,
and the Seebeck coefficient (S) is drastically increased at ~140 K (= T*) with
increasing the Li concentration to show a peak of magnitude ~120 \muV/K in the
S-T curve of x = 0.87. We show that T* corresponds to a crossover temperature
in the conduction, most likely reflecting the correlation-induced temperature
dependence in the low-energy excitations
Complete integrability of derivative nonlinear Schr\"{o}dinger-type equations
We study matrix generalizations of derivative nonlinear Schr\"{o}dinger-type
equations, which were shown by Olver and Sokolov to possess a higher symmetry.
We prove that two of them are `C-integrable' and the rest of them are
`S-integrable' in Calogero's terminology.Comment: 14 pages, LaTeX2e (IOP style), to appear in Inverse Problem
Chaos in a Relativistic 3-body Self-Gravitating System
We consider the 3-body problem in relativistic lineal gravity and obtain an
exact expression for its Hamiltonian and equations of motion. While
general-relativistic effects yield more tightly-bound orbits of higher
frequency compared to their non-relativistic counterparts, as energy increases
we find in the equal-mass case no evidence for either global chaos or a
breakdown from regular to chaotic motion, despite the high degree of
non-linearity in the system. We find numerical evidence for a countably
infinite class of non-chaotic orbits, yielding a fractal structure in the outer
regions of the Poincare plot.Comment: 9 pages, LaTex, 3 figures, final version to appear in Phys. Rev. Let
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