18,579 research outputs found
On Statistical Significance of Signal
A definition for the statistical significance of a signal in an experiment is
proposed by establishing a correlation between the observed p-value and the
normal distribution integral probability, which is suitable for both counting
experiment and continuous test statistics. The explicit expressions to
calculate the statistical significance for both cases are given.Comment: 3 page
Revealing the phase transition behaviors of k-core percolation in random networks
The -core percolation is a fundamental structural transition in complex
networks. Through the analysis of the size jump behaviors of -core in the
evolution process of networks, we confirm that -core percolation is
continuous phase transition when while it is a hybrid
first-order-second-order phase transition when . -core percolation
belongs to different universality class from that of -core (giant component)
percolation. The discontinuity of -core percolation with can be
concluded from largest size jump of -core which will not disappear in the
thermodynamic limit while its continuous characteristic is reflected by second
largest size jump which converges to zero in power law as .
Furthermore, along with the previously known exponent , we obtain a
set of exponents which are independent of when and also different
from those critical exponents of -core and -core percolation
Finite size scaling theory for percolation with multiple giant clusters
A approach of finite size scaling theory for discontinous percolation with
multiple giant clusters is developed in this paper. The percolation in
generalized Bohman-Frieze-Wormald (BFW) model has already been proved to be
discontinuous phase transition. In the evolution process, the size of largest
cluster increases in a stairscase way and its fluctuation shows a series
of peaks corresponding to the jumps of from one stair to another. Several
largest jumps of the size of largest cluster from single edge are studied by
extensive Monte Carlo simulation. which is the mean of
the th largest jump of largest cluster, which is the
corresponding averaged edge density, which is the
standard deviation of and which is the standard
deviation of are analyzed. Rich power law behaviours are found for
, and with critical
exponents denoted as , and . Unlike
continuous percolation where the exact critical thresholds and critical
exponent are used for finite size scaling, the size-dependent pseudo
critical thresholds and works for the data
collapse of the curves of largest cluster and its fluctuation in discontinuous
percolation in BFW model. Further, data collapse can be obtained part by part.
That is, can be collapsed for each jump from one stair to another
and its fluctuation can be collapsed around each peak with the corresponding
and
Finite size scaling theory for percolation phase transition
The finite-size scaling theory for continuous phase transition plays an
important role in determining critical point and critical exponents from the
size-dependent behaviors of quantities in the thermodynamic limit. For
percolation phase transition, the finite-size scaling form for the reduced size
of largest cluster has been extended to cluster ranked . However, this is
invalid for explosive percolation as our results show. Besides, the behaviors
of largest increase of largest cluster induced by adding single link or node
have also been used to investigate the critical properties of percolation and
several new exponents , , and are defined
while their relation with and is unknown. Through the
analysis of asymptotic properties of size jump behaviors, we obtain correct
critical exponents and develop a new approach to finite size scaling theory
where sizes of ranked clusters are averaged at same distances from the
sample-dependent pseudo-critical point in each realization rather than
averaging at same value of control parameter
On the reducibility of some special quadrinomials
Let be positive integers and let be nonzero rational numbers.
We consider the reducibility of some special quadrinomials
with and 5, which related to the study of rational points on certain
elliptic curves or hyperelliptic curves.Comment: 16 pages. Any comments are welcome
Embedding property of -holomorphic curves in Calabi-Yau manifolds for generic
In this paper, we prove that for a generic choice of tame (or compatible)
almost complex structures on a symplectic manifold with
and with its first Chern class , all somewhere
injective -holomorphic maps from any closed smooth Riemann surface into
are \emph{embedded}. We derive this result as a consequence of the general
optimal 1-jet evaluation transversality result of -holomorphic maps in
general symplectic manifolds that we also prove in this paper.Comment: The exposition of the paper much improved with some clarifications in
the Fredholm setting. The proof of 1-jet evaluation transversality is much
clarified by correcting minor error in the Fredholm analysis and making
precise the choice of Sobolev norms in the proof. A few more references are
adde
Floer trajectories with immersed nodes and scale-dependent gluing
We define an enhanced compactification of Floer trajectories under Morse
background using the adiabatic degeneration and the scale-dependent gluing
techniques. The compactification reflects the 1-jet datum of the smooth Floer
trajectories nearby the limiting nodal Floer trajectories arising from
adiabatic degeneration of the background Morse function. This paper studies the
gluing problem when the limiting gradient trajectories has length zero through
a renomalization process. The case with limiting gradient trajectories of
non-zero length will be treated elsewhere.
An immediate application of our result is a proof of the isomorphism property
of the PSS map : A proof of this isomorphism property was first outlined by
P\"unihikin-Salamon-Schwarz \cite{PSS} in a way somewhat different from the
current proof in its details. This kind of scale-dependent gluing techniques
was initiated in [FOOO07] in relation to the metamorphosis of holomorphic
polygons under Lagrangian surgery and is expected to appear in other gluing and
compactification problem of pseudo-holomorphic curves that involves `adiabatic'
parameters or rescales the targets.Comment: 122 pages, 6 figures. Submitted version. Quadratic estimates added,
presentation of error estimates improve
Ultrafast modulation of near-field heat transfer with tunable metamaterials
We propose a mechanism of active near-field heat transfer modulation relying
on externally tunable metamaterials. A large modulation effect is observed and
can be explained by the coupling of surface modes, which is dramatically varied
in the presence of controllable magnetoelectric coupling in metamaterials. We
finally discuss how a practical picosecond-scale thermal modulator can be made.
This modulator allows manipulating nanoscale heat flux in an ultrafast and
noncontact (by optical means) manner.Comment: 11 pages, 2 figure
Thick-thin Decomposition of Floer Trajectories and Adiabatic Gluing
This is a sequel to [OZ1] in which we studied the adiabatic degeneration of
Floer trajectories to "disk-flow-disk" configurations and the recovering
gluing, where the gradient flow part had length 0. In the present paper we
study the case when the gradient flow part has a positive length. Unlike the
standard gluing problem, we study the problem of gluing 1-dimensional gradient
segments and 2-dimensional (perturbed) J-holomorphic curves. The two also have
different convergence rates near the ends: linear convergence for the finite
gradient segments and exponential convergence for J-holomorphic maps.
As an immediate application, we outline the proof that when a finite number
of Hamiltonian deformations of a non-exact Lagrangian submanifold collapse
simultaneously, the pearl complex moduli spaces used in [BC] are diffeomorphic
to the J-holomorphic polygon moduli spaces in [FOOO] provided the dimension of
the moduli spaces is sufficiently small. This is enough to prove that the
A_{\infty}-structures appearing in the two pictures are isomorphic to each
other. The main gluing theorem also provides another proof of the isomorphism
property of PSS map which is different from that of [OZ1]: It bypasses the
nodal Floer trajectories by going directly from "disk-flow-disk" configurations
to resolved Floer trajectories.Comment: 82 pages, 1 figure. Submitted version. Section 14 expanded. Improved
expositio
The Complete Structure of the Cohomology Ring and Associated Symmetries in String Theory
We determine explicitly all structure constants of the whole chiral BRST
cohomology ring in string theory including both the discrete states and
tachyon states. This is made possible by establishing several identities for
Schur polynomials with operator argument and exploring associativity.
Furthermore we find that the (chiral) symmetry algebra of the charges obtained
by using the descent equations can actually be read off from the cohomology
ring structure by simple operation involving the ghost field . We also
determine the enlarged symmetry algebra which contains the charges having ghost
number and . Finally the complete symmetry transformation rules are
derived for closed string discrete states by carefully combining the left and
right sectors. It turns out that the new states introduced recently by Witten
and Zwiebach are naturally created when symmetries act on the old states.Comment: 48 pages, UU-HEP/92/6, with postscript file for one figure; with
input line correcte
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