4,012 research outputs found
Wrapped membranes, matrix string theory and an infinite dimensional Lie algebra
We examine the algebraic structure of the matrix regularization for the
wrapped membrane on in the light-cone gauge. We give a
concrete representation for the algebra and obtain the matrix string theory
having the boundary conditions for the matrix variables corresponding to the
wrapped membrane, which is referred to neither Seiberg and Sen's arguments nor
string dualities. We also embed the configuration of the multi-wrapped membrane
in matrix string theory.Comment: 19 pages, 1 figure, references added, minor change
(p,q)-string in matrix-regularized membrane and type IIB duality
We consider a lightcone wrapped supermembrane compactified on 2-torus in the
matrix regularization. We examine the double dimensional reduction technique
and deduce the free matrix string of (p,q)-string in type IIB superstring
theory explicitly from the matrix-regularized wrapped supermembrane. In
addition we obtain the (2+1)-dimensional super Yang-Mills action in curved
background. We also examine the duality.Comment: 25 page
Comments on the global constraints in light-cone string and membrane theories
In the light-cone closed string and toroidal membrane theories, we associate
the global constraints with gauge symmetries. In the closed string case, we
show that the physical states defined by the BRS charge satisfy the
level-matching condition. In the toroidal membrane case, we show that the
Faddeev-Popov ghost and anti-ghost corresponding to the global constraints are
essentially free even if we adopt any gauge fixing condition for the local
constraint. We discuss the quantum double-dimensional reduction of the wrapped
supermembrane with the global constraints.Comment: 12 pages, typos corrected, to appear in JHE
Flat Foldings of Plane Graphs with Prescribed Angles and Edge Lengths
When can a plane graph with prescribed edge lengths and prescribed angles
(from among \}) be folded flat to lie in an
infinitesimally thin line, without crossings? This problem generalizes the
classic theory of single-vertex flat origami with prescribed mountain-valley
assignment, which corresponds to the case of a cycle graph. We characterize
such flat-foldable plane graphs by two obviously necessary but also sufficient
conditions, proving a conjecture made in 2001: the angles at each vertex should
sum to , and every face of the graph must itself be flat foldable.
This characterization leads to a linear-time algorithm for testing flat
foldability of plane graphs with prescribed edge lengths and angles, and a
polynomial-time algorithm for counting the number of distinct folded states.Comment: 21 pages, 10 figure
Correlation between magnetic and transport properties of phase separated LaCaMnO
The effect of low magnetic fields on the magnetic and electrical transport
properties of polycrystalline samples of the phase separated compound
LaCaMnO is studied. The results are interpreted in the
framework of the field induced ferromagnetic fraction enlargement mechanism. A
fraction expansion coefficient af, which relates the ferromagnetic fraction f
with the applied field H, was obtained. A phenomenological model to understand
the enlargement mechanism is worked out.Comment: 3 pages, 3 figures, presented at the Fifth LAW-MMM, to appear in
Physica B, Minor change
Navigating the Cultural Landscape towards Self-Determination: Results of an Exploratory Study in American Samoa
The American Samoa University Center for Excellence in Developmental Disabilities, Education, Research, and Service (AS-UCEDD) with the University of Hawaii Center on Disability Studies, conducted an exploratory study to better understand how state agencies deliver services, and how disability is perceived by agency staff and consumers in American Samoa. While it initially was envisioned as a needs-sensing study that used surveys and targeted database reviews to systematically capture client needs, the study transformed to a largely qualitative preliminary investigation that was dependent on personal interviews. Findings revealed how contextual, linguistic, and cultural factors play a hugely important role when researching western-based ideals and concepts within indigenous communities
Spatial and temporal filtering of a 10-W Nd:YAG laser with a Fabry-Perot ring-cavity premode cleaner
We report on the use of a fixed-spacer FabryâPerot ring cavity to filter spatially and temporally a 10-W laser-diode-pumped Nd:YAG master-oscillator power amplifier. The spatial filtering leads to a 7.6-W TEMinfinity beam with 0.1% higher-order transverse mode content. The temporal filtering reduces the relative power fluctuations at 10 MHz to 2.8 x 10^-/sqrtHz, which is 1 dB above the shot-noise limit for 50 mA of detected photocurrent
Insights into pulmonary phosphate homeostasis and osteoclastogenesis emerge from the study of pulmonary alveolar microlithiasis
Pulmonary alveolar microlithiasis is an autosomal recessive lung disease caused by a deficiency in the pulmonary epithelial Npt2b sodium-phosphate co-transporter that results in accumulation of phosphate and formation of hydroxyapatite microliths in the alveolar space. The single cell transcriptomic analysis of a pulmonary alveolar microlithiasis lung explant showing a robust osteoclast gene signature in alveolar monocytes and the finding that calcium phosphate microliths contain a rich protein and lipid matrix that includes bone resorbing osteoclast enzymes and other proteins suggested a role for osteoclast-like cells in the host response to microliths. While investigating the mechanisms of microlith clearance, we found that Npt2b modulates pulmonary phosphate homeostasis through effects on alternative phosphate transporter activity and alveolar osteoprotegerin, and that microliths induce osteoclast formation and activation in a receptor activator of nuclear factor-ÎșB ligand and dietary phosphate dependent manner. This work reveals that Npt2b and pulmonary osteoclast-like cells play key roles in pulmonary homeostasis and suggest potential new therapeutic targets for the treatment of lung disease
Zipper unfolding of domes and prismoids
We study Hamiltonian unfoldingâcutting a convex polyhedron along a Hamiltonian path of edges to unfold it without overlapâof two classes of polyhedra. Such unfoldings could be implemented by a single zipper, so they are also known as zipper edge unfoldings. First we consider domes, which are simple convex polyhedra. We find a family of domes whose graphs are Hamiltonian, yet any Hamiltonian unfolding causes overlap, making the domes Hamiltonian-ununfoldable. Second we turn to prismoids, which are another family of simple convex polyhedra. We show that any nested prismoid is Hamiltonian-unfoldable, and that for general prismoids, Hamiltonian unfoldability can be tested in polynomial time.National Science Foundation (U.S.) (Origami Design for Integration of Self-assembling Systems for Engineering Innovation Grant EFRI-1240383)National Science Foundation (U.S.) (Expedition Grant CCF-1138967
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