129,668 research outputs found
A generalization of contact metric manifolds
We give a characterization of a contact metric manifold as a special almost
contact metric manifold and discuss an almost contact metric manifold which is
{a} natural generalization of the contact metric manifolds introduced by Y.
Tashiro.Comment: 15 page
A proof of the Chern-Gauss-Bonnet theorem for indefinite signature metrics using analytic continuation
We derive the Chern-Gauss-Bonnet Theorem for manifolds with smooth
non-degenerate boundary in the pseudo-Riemannian context from the corresponding
result in the Riemannian setting by examining the Euler-Lagrange equations
associated to the Pfaffian of a complex "metric" on the tangent space and then
applying analytic continuation.Comment: This paper has been withdrawn by the authors. A later improved
version is available upon request from the authors but will not be posted to
the arXi
Nanoscale Topographical Replication of Graphene Architecture by Artificial DNA nanostructures
Despite many studies on how geometry can be used to control the electronic
properties of graphene, certain limitations to fabrication of designed graphene
nanostructures exist. Here, we demonstrate controlled topographical replication
of graphene by artificial deoxyribonucleic acid (DNA) nanostructures. Owing to
the high degree of geometrical freedom of DNA nanostructures, we controlled the
nanoscale topography of graphene. The topography of graphene replicated from
DNA nanostructures showed enhanced thermal stability and revealed an
interesting negative temperature coefficient of sheet resistivity when
underlying DNA nanostructures were denatured at high temperatures.Comment: 12 pages, 3 figure
Strong Confinement and Oscillations in Two-Component Bose-Einstein Condensates
We present a new model of BEC dynamics based on strong confinement near the
ground state. The model predicts oscillations in a two-component condensate,
based on interference of non-spreading wave packets moving within a pair of
tilted nearly square potentials. The oscillations are similar to those recently
reported for a magnetically trapped Rb condensate, and the model's
predictions give good quantitative agreement with the experiments.Comment: 4 pages, 8 figure
Correction to "minimal unit vector fields"
The paper "Minimal unit vector fields" by O. Gil-Medrano and E.
Llinares-Fuster \cite{GilLli1}. is a seminal paper in the field that has been
cited by many authors. It contains, however, a minor technical mistake in
Theorem 14 that is important to fix. In this short note, we will provide a
correction to that result.Comment: 8page
Complex sine-Gordon Theory for Coherent Optical Pulse Propagation
It is shown that the McCall-Hahn theory of self-induced transparency in
coherent optical pulse propagation can be identified with the complex
sine-Gordon theory in the sharp line limit. We reformulate the theory in terms
of the deformed gauged Wess-Zumino-Witten sigma model and address various new
aspects of self-induced transparency.Comment: 8 pages, in Late
Fabrication of Analog Electronics for Serial Readout of Silicon Strip Sensors
A set of analog electronics boards for serial readout of silicon strip
sensors was fabricated. A commercially available amplifier is mounted on a
homemade hybrid board in order to receive analog signals from silicon strip
sensors. Also, another homemade circuit board is fabricated in order to
translate amplifier control signals into a suitable format and to provide bias
voltage to the amplifier as well as to the silicon sensors. We discuss
technical details of the fabrication process and performance of the circuit
boards we developed.Comment: minor typos corrected, and additional acknowledgement included. To be
submitted to JINS
Nonabelian sine-Gordon theory and its application to nonlinear optics
Using a field theory generalization of the spinning top motion, we construct
nonabelian generalizations of the sine-Gordon theory according to each
symmetric spaces. A Lagrangian formulation of these generalized sine-Gordon
theories is given in terms of a deformed gauged Wess-Zumino-Witten action which
also accounts for integrably perturbed coset conformal field theories. As for
physical applications, we show that they become precisely the effective field
theories of self-induced transparency in nonlinear optics. This provides a
dictionary between field theory and nonlinear optics.Comment: 5 pages, to appear in the Proceedings of the 2nd Sakharov Conference
on Physics, Moscow, May, 199
Effective Field Theory for Coherent Optical Pulse Propagation
Hidden nonabelian symmetries in nonlinear interactions of radiation with
matter are clarified. In terms of a nonabelian potential variable, we construct
an effective field theory of self-induced transparency, a phenomenon of
lossless coherent pulse propagation, in association with Hermitian symmetric
spaces . Various new properties of self-induced transparency, e.g. soliton
numbers, effective potential energy, gauge symmetry and discrete symmetries,
modified pulse area, conserved -charge etc. are addressed and elaborated
in the nondegenerate two-level case where . Using the
-charge conservation, a new type of analysis on pulse stability is given
which agrees with earlier numerical results.Comment: 41 pages, Latex fil
Complex sine-Gordon Equation in Coherent Optical Pulse Propagation
It is shown that the McCall-Hahn theory of self-induced transparency in
coherent optical pulse propagation can be identified with the complex
sine-Gordon theory in the sharp line limit. We reformulate the theory in terms
of the deformed gauged Wess-Zumino-Witten sigma model and address various new
aspects of self-induced transparency
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