1,156 research outputs found
Five-Dimensional Supersymmetric Yang-Mills Theories and Random Plane Partitions
Five-dimensional supersymmetric Yang-Mills theories are
investigated from the viewpoint of random plane partitions. It is shown that
random plane partitions are factorizable as q-deformed random partitions so
that they admit the interpretations as five-dimensional Yang-Mills and as
topological string amplitudes. In particular, they lead to the exact partition
functions of five-dimensional supersymmetric Yang-Mills with
the Chern-Simons terms. We further show that some specific partitions, which we
call the ground partitions, describe the perturbative regime of the gauge
theories. We also argue their role in string theory. The gauge instantons give
the deformation of the ground partition.Comment: 33 pages, 9 figures, typos correcte
Synthesis and physical properties of (Pb0.5M0.5)(Sr,La)2CuOz (z~5; M = Fe, Co, Cu, and Zn)
(Pb0.5Cu0.5)(Sr0.5La0.5)2CuOz (abbreviated as (Pb,Cu)-"1-2-0-1") with
superconducting transition temperature (Tc) of 25 K is a member (n = 1) of one
of the homologous series of cuprate superconductors,
(Pb4+,Cu2+)(Sr2+,Ln3+)2(Y3+,Ca2+)n-1Cu2+nO2-2n+3 (n = 1-4; Ln: lanthanoid
elements). For the (Pb,Cu)-"1-2-0-1", substitution effects of 3d transition
metal elements M (M = Fe, Co, and Zn) for the Cu site in the (Pb,Cu)-O
charge-reservoir layer (labelled as Cu(1)) are systematically investigated.
Because Fe, Co and Ni ions exist as divalent or trivalent in ionic crystals,
the Sr2+/La3+ ratio in the (Sr,Ln) site is adjusted to satisfy charge
neutrality, assuming that they are in a trivalent state. This results in the
successful synthesis of new materials with nominal compositions of
(Pb0.5M0.5)(Sr0.75La0.25)2CuOz (M = Fe and Co). This observation suggests that
Fe and Co are trivalent in "1-2-0-1". For M = Zn, the nominal composition of
(Pb0.5Zn0.5)(Sr0.5La0.5)2CuOz was found to yield a nearly single "1-2-0-1"
phase. Temperature dependence of electrical resistivity and magnetization were
measured, and superconductivity was confirmed only for the case of M = Zn with
a Tc of 19.7 K. For these three materials, the distribution of Fe, Co and Zn
between Cu(1) and another Cu site in the Cu-O2 plane labelled as Cu(2) was
investigated employing transmission electron microscopy, which showed that Fe,
Co, and Zn occupy both the Cu(1) and Cu(2) sites.Comment: 26 pages, 10 figure
Free Fermion and Seiberg-Witten Differential in Random Plane Partitions
A model of random plane partitions which describes five-dimensional
supersymmetric SU(N) Yang-Mills is studied. We compute the wave
functions of fermions in this statistical model and investigate their
thermodynamic limits or the semi-classical behaviors. These become of the WKB
type at the thermodynamic limit. When the fermions are located at the main
diagonal of the plane partition, their semi-classical wave functions are
obtained in a universal form. We further show that by taking the
four-dimensional limit the semi-classical wave functions turn to live on the
Seiberg-Witten curve and that the classical action becomes precisely the
integral of the Seiberg-Witten differential. When the fermions are located away
from the main diagonal, the semi-classical wave functions depend on another
continuous parameter. It is argued that they are related with the wave
functions at the main diagonal by the renormalization group flow of the
underlying gauge theory.Comment: 32 pages, 3 figures, typos correcte
Gravitational Quantum Foam and Supersymmetric Gauge Theories
We study K\"{a}hler gravity on local SU(N) geometry and describe precise
correspondence with certain supersymmetric gauge theories and random plane
partitions. The local geometry is discretized, via the geometric quantization,
to a foam of an infinite number of gravitational quanta. We count these quanta
in a relative manner by measuring a deviation of the local geometry from a
singular Calabi-Yau threefold, that is a A_{N-1} singularity fibred over
\mathbb{P}^1. With such a regularization prescription, the number of the
gravitational quanta becomes finite and turns to be the perturbative
prepotential for five-dimensional \mathcal{N}=1 supersymmetric SU(N)
Yang-Mills. These quanta are labelled by lattice points in a certain convex
polyhedron on \mathbb{R}^3. The polyhedron becomes obtainable from a plane
partition which is the ground state of a statistical model of random plane
partition that describes the exact partition function for the gauge theory.
Each gravitational quantum of the local geometry is shown to consist of N unit
cubes of plane partitions.Comment: 43 pages, 12 figures: V2 typos correcte
Correction of Anophthalmic Enophthalmos with a Three-Staged Procedure: Two Case Reports
Surgical correction of an anophthalmic enophthalmos secondary to inappropriate repair of the eye socket involves several difficult aesthetic issues associated with long-term use of a poorly fitting prosthetic eye. In this paper, we present two cases of anophthalmic enophthalmos. During the treatment of the first patient, unsatisfactory cosmetic problems including lower eyelid retraction, hypoglobus, and severe upper eyelid ptosis were revealed. Accordingly, a three-staged procedure was performed on the second patient, including autologous augmentation of the eye socket, correction of lower eyelid retraction with a cartilage graft, and a frontalis sling procedure to correct upper eyelid ptosis
Fabrication of Bi2212 Cross Whiskers Junction
An intrinsic Josephson junction has been successfully fabricated without any
micro-fabrication technique. Two Bi2212 whiskers were crossed with one another
and joined by post-annealing. The inter-whisker electrical transport properties
were measured by the four-probe method. The temperature dependence of
resistance exhibited metallic behavior above TC. The resistance decreased to
zero around 80K, corresponding to the superconducting transition. The
current-voltage characteristics at 5K exhibited a small hysteresis and voltage
jump, which can be explained by the intrinsic Josephson effect.Comment: 3 page PDF fil
A Cross-Whiskers Junction as a Novel Fabrication Process for Intrinsic Josephson Junction
A Bi2Sr2CaCu2O8+d cross-whiskers junction has been successfully discovered as
a novel intrinsic Josephson junction without using any technique for
micro-fabrication. Two Bi2Sr2CaCu2O8+d whisker crystals were placed crosswise
on a MgO substrate and heated at 850C for 30 min. They were electrically
connected at their c-planes. The measurement terminals were made at the four
ends of the whiskers. The I-V characteristics of the cross-whiskers junction at
5K were found to show a clear multiple-branch structure with a spacing of
approximately 15 mV that is a feature of the intrinsic Josephson junction. The
critical current density Jc was estimated to be 1170 A/cm2. The
branch-structure was strongly suppressed by the magnetic field above 1kOe.Comment: 4 pages, PDF fil
1/R gravity and Scalar-Tensor Gravity
We point out that extended gravity theories, the Lagrangian of which is an
arbitrary function of scalar curvature , are equivalent to a class of the
scalar tensor theories of gravity. The corresponding gravity theory is
Brans-Dicke gravity with a potential for the Brans-Dicke scalar
field, which is not compatible with solar system experiments if the field is
very light: the case when such modifications are important recently.Comment: 4 pages, to appear in PL
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