5,763 research outputs found
New Supersymmetric Solutions in N=2 Matter Coupled AdS_3 Supergravities
We construct new 1/2 supersymmetric solutions in D=3, N=2, matter coupled,
U(1) gauged supergravities and study some of their properties. We do this by
employing a quite general supersymmetry breaking condition, from which we also
redrive some of the already known solutions. Among the new solutions, we have
an explicit non-topological soliton for the non-compact sigma model, a locally
flat solution for the compact sigma model and a string-like solution for both
types of sigma models. The last one is smooth for the compact scalar manifold.Comment: 1+21 pages, 2 figures, LaTeX2e, JHEP style; v2: added one reference +
made minor changes and added a few comments to clarify the presentatio
Genome-wide analyses of Liberibacter species provides insights into evolution, phylogenetic relationships, and virulence factors.
'Candidatus Liberibacter' species are insect-transmitted, phloem-limited α-Proteobacteria in the order of Rhizobiales. The citrus industry is facing significant challenges due to huanglongbing, associated with infection from 'Candidatus Liberibacter asiaticus' (Las). In order to gain greater insight into 'Ca. Liberibacter' biology and genetic diversity, we have performed genome sequencing and comparative analyses of diverse 'Ca. Liberibacter' species, including those that can infect citrus. Our phylogenetic analysis differentiates 'Ca. Liberibacter' species and Rhizobiales in separate clades and suggests stepwise evolution from a common ancestor splitting first into nonpathogenic Liberibacter crescens followed by diversification of pathogenic 'Ca. Liberibacter' species. Further analysis of Las genomes from different geographical locations revealed diversity among isolates from the United States. Our phylogenetic study also indicates multiple Las introduction events in California and spread of the pathogen from Florida to Texas. Texan Las isolates were closely related, while Florida and Asian isolates exhibited the most genetic variation. We have identified conserved Sec translocon (SEC)-dependent effectors likely involved in bacterial survival and virulence of Las and analysed their expression in their plant host (citrus) and insect vector (Diaphorina citri). Individual SEC-dependent effectors exhibited differential expression patterns between host and vector, indicating that Las uses its effector repertoire to differentially modulate diverse organisms. Collectively, this work provides insights into the evolution of 'Ca. Liberibacter' species, the introduction of Las in the United States and identifies promising Las targets for disease management
Embedding of theories with SU(2|4) symmetry into the plane wave matrix model
We study theories with SU(2|4) symmetry, which include the plane wave matrix
model, 2+1 SYM on RxS^2 and N=4 SYM on RxS^3/Z_k. All these theories possess
many vacua. From Lin-Maldacena's method which gives the gravity dual of each
vacuum, it is predicted that the theory around each vacuum of 2+1 SYM on RxS^2
and N=4 SYM on RxS^3/Z_k is embedded in the plane wave matrix model. We show
this directly on the gauge theory side. We clearly reveal relationships among
the spherical harmonics on S^3, the monopole harmonics and the harmonics on
fuzzy spheres. We extend the compactification (the T-duality) in matrix models
a la Taylor to that on spheres.Comment: 56 pages, 6 figures, v2:a footnote and references added, section 5.2
improved, typos corrected, v3:typos corrected, v4: some equations are
corrected, eq.(G.2) is added, conclusion is unchange
Kinetic Parameters Evaluation for Isoprene Mixed with Aluminum Oxide
AbstractWe analyzed the basic hazard characteristics for isoprene in the manufacturing process by evaluating the runaway reaction, kinetic parameters and safety parameters in this study. Experiments were carried out by calculating the thermal decomposition reactions for isoprene and mixed with aluminum oxide in non-isothermal conditions by differential scanning calorimetry (DSC). Afterwards results indicated that isoprene had a conjugated double bond of unstable structure, and therefore it was prone to produce exothermic reaction during the process of polymerization. Aluminum oxide was applied to mix with isoprene, which could increase the heat release rate. Based on the results, safety information should be provided to government and relevant industries for prevention the accident occur in relevant plants
Information Recovery From Black Holes
We argue that if black hole entropy arises from a finite number of underlying
quantum states, then any particular such state can be identified from infinity.
The finite density of states implies a discrete energy spectrum, and, in
general, such spectra are non-degenerate except as determined by symmetries.
Therefore, knowledge of the precise energy, and of other commuting conserved
charges, determines the quantum state. In a gravitating theory, all conserved
charges including the energy are given by boundary terms that can be measured
at infinity. Thus, within any theory of quantum gravity, no information can be
lost in black holes with a finite number of states. However, identifying the
state of a black hole from infinity requires measurements with Planck scale
precision. Hence observers with insufficient resolution will experience
information loss.Comment: First prize in the Gravity Research Foundation Essay Competition, 8
pages, Late
Thermodynamics of R-charged Black Holes in AdS(5) From Effective Strings
It is well known that the thermodynamics of certain near-extremal black holes
in asymptotically flat space can be lifted to an effective string description
created from the intersection of D-branes. In this paper we present evidence
that the semiclassical thermodynamics of near-extremal R-charged black holes in
AdS(5)xS(5) is described in a similar manner by effective strings created from
the intersection of giant gravitons on the S(5). We also present a free fermion
description of the supersymmetric limit of the one-charge black hole, and we
give a crude catalog of the microstates of the two and three-charge black holes
in terms of operators in the dual conformal field theory.Comment: v2: references and typos corrected, 24 pages, latex2
Enhanced Bound State Formation in Two Dimensions via Stripe-Like Hopping Anisotropies
We have investigated two-electron bound state formation in a square
two-dimensional t-J-U model with hopping anisotropies for zero electron
density; these anisotropies are introduced to mimic the hopping energies
similar to those expected in stripe-like arrangements of holes and spins found
in various transition metal oxides. In this report we provide analytical
solutions to this problem, and thus demonstrate that bound-state formation
occurs at a critical exchange coupling, J_c, that decreases to zero in the
limit of extreme hopping anisotropy t_y/t_x -> 0. This result should be
contrasted with J_c/t = 2 for either a one-dimensional chain, or a
two-dimensional plane with isotropic hopping. Most importantly, this behaviour
is found to be qualitatively similar to that of two electrons on the two-leg
ladder problem in the limit of t_interchain/t_intrachain -> 0. Using the latter
result as guidance, we have evaluated the pair correlation function, thus
determining that the bound state corresponds to one electron moving along one
chain, with the second electron moving along the opposite chain, similar to two
electrons confined to move along parallel, neighbouring, metallic stripes. We
emphasize that the above results are not restricted to the zero density limit -
we have completed an exact diagonalization study of two holes in a 12 X 2
two-leg ladder described by the t-J model and have found that the
above-mentioned lowering of the binding energy with hopping anisotropy persists
near half filling.Comment: 6 pages, 3 eps figure
On dilatation operator for a renormalizable theory
Given a renormalizable theory we construct the dilatation operator, in the
sense of generator of RG flow of composite operators. The generator is found as
a differential operator acting on the space of normal symbols of composite
operators in the theory. In the spirit of AdS/CFT correspondence, this operator
is interpreted as the Hamiltonian of the dual theory. In the case of a field
theory with non-abelian gauge symmetry the resulting system is a matrix model.
The one-loop case is analyzed in details and it is shown that we reproduce
known results from N=4 supersymmetric Yang-Mills theory.Comment: 26 pages, no figure
On gravitational description of Wilson lines
We study solutions of Type IIB supergravity, which describe the geometries
dual to supersymmetric Wilson lines in N=4 super-Yang-Mills. We show that the
solutions are uniquely specified by one function which satisfies a Laplace
equation in two dimensions. We show that if this function obeys a certain
Dirichlet boundary condition, the corresponding geometry is regular, and we
find a simple interpretation of this boundary condition in terms of D3 and D5
branes which are dissolved in the geometry. While all our metrics have AdS_5 x
S^5 asymptotics, they generically have nontrivial topologies, which can be
uniquely specified by a set of non-contractible three- and five-spheres.Comment: 46 page
Surface and capillary transitions in an associating binary mixture model
We investigate the phase diagram of a two-component associating fluid mixture
in the presence of selectively adsorbing substrates. The mixture is
characterized by a bulk phase diagram which displays peculiar features such as
closed loops of immiscibility. The presence of the substrates may interfere the
physical mechanism involved in the appearance of these phase diagrams, leading
to an enhanced tendency to phase separate below the lower critical solution
point. Three different cases are considered: a planar solid surface in contact
with a bulk fluid, while the other two represent two models of porous systems,
namely a slit and an array on infinitely long parallel cylinders. We confirm
that surface transitions, as well as capillary transitions for a large
area/volume ratio, are stabilized in the one-phase region. Applicability of our
results to experiments reported in the literature is discussed.Comment: 12 two-column pages, 12 figures, accepted for publication in Physical
Review E; corrected versio
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