13,708 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
Kovacs Effect in a Fragile Glass Model
The Kovacs protocol, based on the temperature shift experiment originally
conceived by A.J. Kovacs for glassy polymers, is implemented in an exactly
solvable dynamical model. This model is characterized by interacting fast and
slow modes represented respectively by spherical spins and harmonic oscillator
variables. Due to this fundamental property, the model reproduces the
characteristic non-monotonic evolution known as the ``Kovacs effect'', observed
in polymers, in granular materials and models of molecular liquids, when
similar experimental protocols are implemented.Comment: 8 pages, 6 figure
Center vortices on SU(2) lattices
We show that gauge invariant definition of thin, thick and hybrid center
vortices, defined by Kovacs and Tomboulis on SO(3) x Z(2) configurations, can
also be defined in SU(2). We make this connection using the freedom of choosing
a particular SU(2) representative of SO(3). We further show that in another
representative the Tomboulis \sigma - \eta thin vortices are P (projection)
vortices. The projection approximation corresponds to dropping the perimeter
factor of a Wilson loop after appropriate gauge fixing. We present results for
static quark potentials based on these vortex counters and compare pojection
vortex counters with gauge invariant ones on the same configuration.Comment: LaTe
The localization transition in SU(3) gauge theory
We study the Anderson-like localization transition in the spectrum of the
Dirac operator of quenched QCD. Above the deconfining transition we determine
the temperature dependence of the mobility edge separating localized and
delocalized eigenmodes in the spectrum. We show that the temperature where the
mobility edge vanishes and localized modes disappear from the spectrum,
coincides with the critical temperature of the deconfining transition. We also
identify topological charge related close to zero modes in the Dirac spectrum
and show that they account for only a small fraction of localized modes, a
fraction that is rapidly falling as the temperature increases.Comment: 7 pages, 5 figures, v3: additional data on finer lattice; final,
published versio
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
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