1,071 research outputs found
Polynomial Approach and Non-linear Analysis for a Traffic Fundamental Diagram
Vehicular traffic can be modelled as a dynamic discrete form. As in many dynamic systems, the parameters modelling traffic can produce a number of different trajectories or orbits, and it is possible to depict different flow situations, including chaotic ones. In this paper, an approach to the wellknown density-flow fundamental diagram is suggested, using an analytical polynomial technique, in which coefficients are taken from significant values acting as the parameters of the traffic model. Depending on the values of these parameters, it can be seen how the traffic flow changes from stable endpoints to chaotic trajectories, with proper analysis in their stability features
Structure of the medium formed in heavy ion collisions
We investigate the structure of the medium formed in heavy ion collisions
using three different models: the Color String Percolation Model (CSPM), the
Core-Shell-Color String Percolation Model (CSCSPM), and the Color Glass
Condensate (CGC) framework. We analyze the radial distribution function of the
transverse representation of color flux tubes in each model to determine the
medium's structure. Our results indicate that the CSPM behaves as an ideal gas,
while the CSCSPM exhibits a structural phase transition from a gas-like to a
liquid-like structure. Additionally, our analysis of the CGC framework suggests
that it produces systems that behave like interacting gases for AuAu central
collisions at RHIC energies and liquid-like structures for PbPb central
collisions at LHC energies.Comment: 15 pages, 8 figure
The U(1)-Higgs Model: Critical Behaviour in the Confinig-Higgs region
We study numerically the critical properties of the U(1)-Higgs lattice model,
with fixed Higgs modulus, in the region of small gauge coupling where the Higgs
and Confining phases merge. We find evidence of a first order transition line
that ends in a second order point. By means of a rotation in parameter space we
introduce thermodynamic magnitudes and critical exponents in close resemblance
with simple models that show analogous critical behaviour. The measured data
allow us to fit the critical exponents finding values in agreement with the
mean field prediction. The location of the critical point and the slope of the
first order line are accurately given.Comment: 21 text pages. 12 postscript figures available on reques
Dynamical generation of a gauge symmetry in the Double-Exchange model
It is shown that a bosonic formulation of the double-exchange model, one of the classical models for magnetism, generates dynamically a gauge-invariant phase in a finite region of the phase diagram. We use analytical methods, Monte Carlo simulations and Finite-Size Scaling analysis. We study the transition line between that region and the paramagnetic phase. The numerical results show that this transition line belongs to the Universality Class of the Antiferromagnetic RP(2) model. The fact that one can define a Universality Class for the Antiferromagnetic RP(2) model, different from the one of the O(N) models, is puzzling and somehow contradicts naive expectations about Universality
Lactococcus lactis subsp. lactis infection in waterfowl: first confirmation in animals.
We report the first description, confirmed by bacteriologic and molecular (polymerase chain reaction and pulsed-field gel electrophoresis) analysis, of an infection in animals caused by Lactococcus lactis subsp. lactis, affecting waterfowl
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