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Algorithms for network piecewise-linear programs
In this paper a subarea of Piecewise-Linear Programming named network Piecewise-Linear Programming (NPLP) is discussed. Initially the problem formulation, main efinitins and related Concepts are presented. In the sequence of the paper, four specialized algorithms for NPLP, as well as the results of a preliminary computational study, are presented
Phase transition for the frog model
We study a system of simple random walks on graphs, known as frog model. This
model can be described as follows: There are active and sleeping particles
living on some graph G. Each active particle performs a simple random walk with
discrete time and at each moment it may disappear with probability 1-p. When an
active particle hits a sleeping particle, the latter becomes active. Phase
transition results and asymptotic values for critical parameters are presented
for Z^d and regular trees
Time series analysis for minority game simulations of financial markets
The minority game (MG) model introduced recently provides promising insights
into the understanding of the evolution of prices, indices and rates in the
financial markets. In this paper we perform a time series analysis of the model
employing tools from statistics, dynamical systems theory and stochastic
processes. Using benchmark systems and a financial index for comparison,
several conclusions are obtained about the generating mechanism for this kind
of evolut ion. The motion is deterministic, driven by occasional random
external perturbation. When the interval between two successive perturbations
is sufficiently large, one can find low dimensional chaos in this regime.
However, the full motion of the MG model is found to be similar to that of the
first differences of the SP500 index: stochastic, nonlinear and (unit root)
stationary.Comment: LaTeX 2e (elsart), 17 pages, 3 EPS figures and 2 tables, accepted for
publication in Physica
Asymptotic safety in higher-derivative gravity
We study the non-perturbative renormalization group flow of higher-derivative
gravity employing functional renormalization group techniques. The
non-perturbative contributions to the -functions shift the known
perturbative ultraviolet fixed point into a non-trivial fixed point with three
UV-attractive and one UV-repulsive eigendirections, consistent with the
asymptotic safety conjecture of gravity. The implication of this transition on
the unitarity problem, typically haunting higher-derivative gravity theories,
is discussed.Comment: 8 pages; 1 figure; revised versio
Coulomb corrections to inclusive cross sections at the future Electron - Ion Collider
The experimental results of the future electron -- ion () collider are
expected to constrain the dynamics of the strong interactions at small values
of the Bjorken -- variable and large nuclei. Recently it has been suggested
that Coulomb corrections can be important in inclusive and diffractive
interactions. In this paper we present a detailed investigation of the impact
of the Coulomb corrections to some of the observables that will be measured in
the future collider. In particular, we estimate the magnitude of these
corrections for the charm and longitudinal cross sections in inclusive and
diffractive interactions. Our results demonstrate that the Coulomb corrections
for these observables are negligible, which implies that they can be used to
probe the QCD dynamics.Comment: 9 pages, 6 figures. Improved version to be published in Physical
Review
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