56,138 research outputs found
A sufficient condition for a balanced bipartite digraph to be hamiltonian
We describe a new type of sufficient condition for a balanced bipartite
digraph to be hamiltonian. Let be a balanced bipartite digraph and be
distinct vertices in . dominates a vertex if
and ; in this case, we call the pair dominating. In
this paper, we prove that a strong balanced bipartite digraph on
vertices contains a hamiltonian cycle if, for every dominating pair of vertices
, either and or and
. The lower bound in the result is sharp.Comment: 12 pages, 3 figure
Quantum Chromodynamics with Many Flavors
We investigate the phase structure of lattice QCD for general number of
flavors . Based on numerical data combined with the results of the
perturbation theory we propose the following picture: When , there
is only one IR fixed point at vanishing gauge coupling, i.e., the theory in the
continuum limit is trivial. On the other hand, when , there
is a non-trivial fixed point. Therefore, the theory is non-trivial with
anomalous dimensions, however, without quark confinement. Theories which
satisfy both quark confinement and spontaneous chiral symmetry breaking in the
continuum limit exist only for .Comment: Talk presented by K. Kanaya at the 1997 Yukawa International Seminar
(YKIS'97) on ``Non-Perturbative QCD --- Structure of the QCD Vacuum ---'',
YITP, Kyoto, Japan, 2--12 Dec. 1997. To be published in the proceedings
[Prog. Theor. Phys. Suppl.
Raman spectra of GexAsySe1−x−y glasses
Various Ge–As–Se glasses spanning a mean coordination number (MCN) from 2.2 to 2.94 have been investigated using differential scanning calorimetry and Raman spectroscopy. The glass transition temperature Tg was found to increase with increasing MCN, except for those glasses located within the nanoscale phase-separated region of the phase diagram. The evolution of Raman features at wavenumbers from 150 to 350 cm⁻¹ exhibits two transitionlike features. Merging of the 225 and 250 cm⁻¹ modes at MCN=2.5 is a symbol of the extinction of Se–Se bonds. Additionally, the appearance of two modes at 280–290 and 170 cm⁻¹ at MCN>2.7 come from the defect modes of ethanelike Ge₂Se₆/₂. The increase in the scattering from these defects is an important factor leading to enhanced optical loss in the glasses with high MCN.This research was partly supported by the Australian
Research Council through its Centres of Excellence and Federation
Fellow Programs
Henry Y. H. Zhao. The uneasy narrator : Chinese fiction from the traditional to the modern
This article reviews the book The Uneasy Narrator: Chinese Fiction from the Traditional to the Modern , written by Henry Y.H. Zhao
Phase structure of QCD for general number of flavors
We investigate and elucidate the phase structure of QCD for general number of
flavors with Wilson quarks, varying from 2 up to 300. Based on
numerical results combined with the result of the perturbation theory we
propose the following picture: When , there is only a trivial fixed
point and therefore the theory in the continuum limit is trivial. On the other
hand, when , there is a non-trivial fixed point and therefore
the theory is non-trivial with anomalous dimensions, however, without quark
confinement. Theories which satisfy both quark confinement and spontaneous
chiral symmetry breaking in the continuum limit exist only for . We
also discuss the structure of the deconfining phase at finite temperatures for
the small number of flavors such as and 3, through a systematic study
of it for general number of flavors.Comment: LaTeX, 7 pages, 10 PS figures, Talk presented at LATTICE96(poster)
and LATTICE96(finite temperature
Germanium-on-silicon mid-infrared waveguides and Mach-Zehnder interferometers
In this paper we describe Ge-on-Si waveguides and Mach-Zehnder interferometers operating in the 5.2 - 5.4 mu m wavelength range. 3dB/cm waveguide losses and Mach-Zehnder interferometers with 20dB extinction ratio are presented
Examples of scalar-flat hypersurfaces in
Given a hypersurface of null scalar curvature in the unit sphere
, , such that its second fundamental form has rank
greater than 2, we construct a singular scalar-flat hypersurface in \Rr^{n+1}
as a normal graph over a truncated cone generated by . Furthermore, this
graph is 1-stable if the cone is strictly 1-stable.Comment: Paper accepted to publication in Manuscripta Mathematic
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