We define a soft-spins approach to the driven lattice gas model (C-DLG) at the level of a master equation. As a result, we obtain a Langevin equation for the C-DLG which depends on the microscopic transition probabilities. We then show how this dependence affects the critical behavior of the the C-DLG, placing the finiteand the infinite-driving-field cases into different universality classes. I...

We construct a second-order continuum traffic model by using an iterative procedure in order to derive a constitutive relation for the traffic pressure which is similar to the Navier–Stokes equation for ordinary fluids. Our second-order traffic model represents an improvement on the traffic model suggested by Kerner and Konhäuser since the iterative procedure introduces, in the constitutive rel...

We construct a continuum model for biological aggregations in which individuals experience long-range social attraction and short-range dispersal. For the case of one spatial dimension, we study the steady states analytically and numerically. There exist strongly nonlinear states with compact support and steep edges that correspond to localized biological aggregations, or clumps. These steady-s...

We study a one-dimensional continuum model for lipid bilayers. The system consists of water and lipid molecules; lipid molecules are represented by two ‘beads’, a head bead and a tail bead, connected by a rigid rod. We derive a simplified model for such a system, in which we only take into account the effects of entropy and hydrophilic/hydrophobic interactions. We show that for this simple mode...

We study properties of the clusters of a system of fully penetrable balls, a model formed by centering equal-sized balls on the points of a Poisson process. We develop a formal expression for the density of connected clusters of k balls (called k-mers) in the system, rst rigorously derived by Penrose 15]. Our integral expressions are free of inherent redundancies, making them more tractable for...

on behalf of the ZEUS collaboration We present results from recent investigations of diffractive vector meson production using the ZEUS detector at HERA. These consist of measurements of ρ 0 production in the region of photon virtuality 0.25 < Q 2 < 0.85 GeV 2 , of ρ 0 , φ, and J/ψ production for values of the momentum transfer to the proton 0.3 < |t| < 4.0 GeV 2 , and of elastic J/ψ production...

We prove from the existence of a Mahlo cardinal the consistency of the statement that 2ω = ω3 holds and every stationary subset of ω2∩cof(ω) reflects to an ordinal less than ω2 with cofinality ω1. Let us say that stationary set reflection holds at ω2 if for any stationary set S ⊆ ω2∩cof(ω), there is an ordinal α ∈ ω2∩cof(ω1) such that S∩α is stationary in α (that is, S reflects to α). In a clas...

The first implementation of a wavelet discretization of the Integral Equation Formalism (IEF) for the Polarizable Continuum Model (PCM) is presented here. The method is based on the application of a general purpose wavelet solver on the cavity boundary to solve the integral equations of the IEF-PCM problem. Wavelet methods provide attractive properties for the solution of the electrostatic prob...

A number of years ago, Widom and Rowlinson proposed a continuum model of interacting spherical particles and provided compelling evidence that this model has a phase transition. A rigorous proof of the existence of a two-phase regime in this model emerged shortly thereafter and recently, this phase transition has been understood in geometric terms—as a percolation phenomenon. Nevertheless, prog...

We present a progression of three distinct three-zone, continuum models for swarm behavior based on social interactions with neighbors in order to explain simple coherent structures in popular biological models of aggregations. In continuum models, individuals are replaced with density and velocity functions. Individual behavior is modeled with convolutions acting within three interaction zones...