11,694 research outputs found
Corner contribution to percolation cluster numbers in three dimensions
In three-dimensional critical percolation we study numerically the number of
clusters, , which intersect a given subset of bonds, . If
represents the interface between a subsystem and the environment, then
is related to the entanglement entropy of the critical diluted
quantum Ising model. Due to corners in there are singular corrections
to , which scale as , being
the linear size of and the prefactor, , is found to be
universal. This result indicates that logarithmic finite-size corrections exist
in the free-energy of three-dimensional critical systems.Comment: 6 pages, 7 figures. arXiv admin note: text overlap with
arXiv:1210.467
Critical behavior and entanglement of the random transverse-field Ising model between one and two dimensions
We consider disordered ladders of the transverse-field Ising model and study
their critical properties and entanglement entropy for varying width, , by numerical application of the strong disorder renormalization group
method. We demonstrate that the critical properties of the ladders for any
finite are controlled by the infinite disorder fixed point of the random
chain and the correction to scaling exponents contain information about the
two-dimensional model. We calculate sample dependent pseudo-critical points and
study the shift of the mean values as well as scaling of the width of the
distributions and show that both are characterized by the same exponent,
. We also study scaling of the critical magnetization, investigate
critical dynamical scaling as well as the behavior of the critical entanglement
entropy. Analyzing the -dependence of the results we have obtained accurate
estimates for the critical exponents of the two-dimensional model:
, and .Comment: 10 pages, 9 figure
Drug-therapy networks and the predictions of novel drug targets
Recently, a number of drug-therapy, disease, drug, and drug-target networks
have been introduced. Here we suggest novel methods for network-based
prediction of novel drug targets and for improvement of drug efficiency by
analysing the effects of drugs on the robustness of cellular networks.Comment: This is an extended version of the Journal of Biology paper
containing 2 Figures, 1 Table and 44 reference
The rich frequency spectrum of the triple-mode variable AC And
Fourier analysis of the light curve of AC And from the HATNet database
reveals the rich frequency structure of this object. Above 30 components are
found down to the amplitude of 3 mmag. Several of these frequencies are not the
linear combinations of the three basic components. We detect period increase in
all three components that may lend support to the Pop I classification of this
variable.Comment: Poster presented at IAU Symposium 301, "Precision Asteroseismology -
Celebration of the Scientific Opus of Wojtek Dziembowski", 19-23 August 2013,
Wroclaw, Polan
Quadratic operators used in deducing exact ground states for correlated systems: ferromagnetism at half filling provided by a dispersive band
Quadratic operators are used in transforming the model Hamiltonian (H) of one
correlated and dispersive band in an unique positive semidefinite form coopting
both the kinetic and interacting part of H. The expression is used in deducing
exact ground states which are minimum energy eigenstates only of the full
Hamiltonian. It is shown in this frame that at half filling, also dispersive
bands can provide ferromagnetism in exact terms by correlation effects .Comment: 7 page
Semi-Empirical Cepheid Period-Luminosity Relations in Sloan Magnitudes
In this paper we derive semi-empirical Cepheid period-luminosity (P-L)
relations in the Sloan ugriz magnitudes by combining the observed BVI mean
magnitudes from the Large Magellanic Cloud Cepheids (LMC) and theoretical
bolometric corrections. We also constructed empirical gr band P-L relations,
using the publicly available Johnson-Sloan photometric transformations, to be
compared with our semi-empirical P-L relations. These two sets of P-L relations
are consistent with each other.Comment: 4 pages, 2 tables and 2 figures, ApJ accepte
Development and characterisation of injection moulded, all-polypropylene composites
In this work, all-polypropylene composites (all-PP composites) were manufactured by injection moulding. Prior
to injection moulding, pre-impregnated pellets were prepared by a three-step process (filament winding, compression
moulding and pelletizing). A highly oriented polypropylene multifilament was used as the reinforcement material, and a
random polypropylene copolymer (with ethylene) was used as the matrix material. Plaque specimens were injection
moulded from the pellets with either a film gate or a fan gate. The compression moulded sheets and injection moulding
plaques were characterised by shrinkage tests, static tensile tests, dynamic mechanical analysis and falling weight impact
tests; the fibre distribution and fibre/matrix adhesion were analysed with light microscopy and scanning electron
microscopy. The results showed that with increasing fibre content, both the yield stress and the perforation energy significantly
increased. Of the two types of gates used, the fan gate caused the mechanical properties of the plaque specimens to
become more homogeneous (i.e., the differences in behaviour parallel and perpendicular to the flow direction became negligible)
Poisson to Random Matrix Transition in the QCD Dirac Spectrum
At zero temperature the lowest part of the spectrum of the QCD Dirac operator
is known to consist of delocalized modes that are described by random matrix
statistics. In the present paper we show that the nature of these eigenmodes
changes drastically when the system is driven through the finite temperature
cross-over. The lowest Dirac modes that are delocalized at low temperature
become localized on the scale of the inverse temperature. At the same time the
spectral statistics changes from random matrix to Poisson statistics. We
demonstrate this with lattice QCD simulations using 2+1 flavors of light
dynamical quarks with physical masses. Drawing an analogy with Anderson
transitions we also examine the mobility edge separating localized and
delocalized modes in the spectrum. We show that it scales in the continuum
limit and increases sharply with the temperature.Comment: 10 pages, 9 eps figures, a few references added and typos correcte
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