Francis J. Alexander

Discrete Models of Complex Fluid Dynamics (2007)

Bruce M. Boghosian, Francis J. Alexander, Peter V. Coveney

e order of once per time step, they effectively allow for time steps comparable to the mean free time --- roughly two orders of magnitude greater than what is possible with MD. The first application...

Equation-free implementation of statistical moment closures (2007)

Alexander, Francis J., Johnson, Gregory, Eyink, Gregory L., Kevrekidis, Ioannis G.

We present a general numerical scheme for the practical implementation of statistical moment closures suitable for modeling complex, large-scale, nonlinear systems. Building on recently developed...

Statistical Mechanics of Histories: A Cluster Monte Carlo Algorithm (2005)

Gulbahce, Natali, Alexander, Francis J., Johnson, Gregory

We present an efficient computational approach to sample the histories of nonlinear stochastic processes. This framework builds upon recent work on casting a $d$-dimensional stochastic dynamical...

Fourier Acceleration of Langevin Molecular Dynamics (2000)

Alexander, Francis J., Boghosian, Bruce M., Brower, Richard C., Kimura, S. Roy

Fourier acceleration has been successfully applied to the simulation of lattice field theories for more than a decade. In this paper, we extend the method to the dynamics of discrete particles moving...

Coulomb field of an accelerated charge: physical and mathematical aspects (1999)

Alexander, Francis J., Gerlach, Ulrich H.

The Maxwell field equations relative to a uniformly accelerated frame, and the variational principle from which they are obtained, are formulated in terms of the technique of geometrical gauge...

Integer Lattice Gases (1998)

Boghosian, Bruce M., Yepez, Jeffrey, Alexander, Francis J., Margolus, Norman H.

We generalize the hydrodynamic lattice gas model to include arbitrary numbers of particles moving in each lattice direction. For this generalization we derive the equilibrium distribution function...

Shape-Dependent Thermodynamics and Non-Local Hydrodynamics in a Non-Gibbsian Steady-State of a Drift-Diffusion System (1998)

Alexander, Francis J., Eyink, Gregory L.

Shape-dependent thermodynamics and non-local hydrodynamics are argued to occur in dissipative steady states of driven diffusive systems. These predictions are confirmed by numerical simulations....

Integer Lattice Gases (1997)

Bruce M. Boghosian, Jeffrey Yepez, Francis J. Alexander, Norman H. Margolus

We generalize the hydrodynamic lattice gas model to include arbitrary numbers of particles moving in each lattice direction. For this generalization we derive the equilibrium distribution function...

Integer Lattice Gases (1997)

Bruce M. Boghosian, Jeffrey Yepez, Francis J. Alexander, Norman H. Margolus

We generalize the hydrodynamic lattice gas model to include arbitrary numbers of particles moving in each lattice direction. For this generalization we derive the equilibrium distribution function...

Turbulence Fluctuations and New Universal Realizability Conditions in Modelling (1996)

Eyink, Gregory L., Alexander, Francis J.

General turbulent mean statistics are shown to be characterized by a variational principle. The variational functionals, or ``effective actions'', have experimental consequences for turbulence...

Rayleigh-Ritz Calculation of Effective Potential Far From Equilibrium (1996)

Alexander, Francis J., Eyink, Gregory L.

We demonstrate the utility of a Rayleigh-Ritz scheme recently proposed to compute the nonequilibrium effective potential nonperturbatively in a strong noise regime far from equilibrium. A simple...

Integer Lattice Gases (1996)

Boghosian, Bruce M., Yepez, Jeffrey, Alexander, Francis J., Margolus, Norman H.

We generalize the hydrodynamic lattice gas model to include arbitrary numbers of particles moving in each lattice direction. For this generalization we derive the equilibrium distribution function...

Statistical Mechanics of Kinks in (1+1)-Dimensions: Numerical Simulations and Double Gaussian Approximation (1993)

Alexander, Francis J., Habib, Salman, Kovner, Alex

We investigate the thermal equilibrium properties of kinks in a classical $\F^4$ field theory in $1+1$ dimensions. From large scale Langevin simulations we identify the temperature below which a...

Statistical Mechanics of Kinks in (1+1)-Dimensions (1992)

Alexander, Francis J., Habib, Salman

We investigate the thermal equilibrium properties of kinks in a classical $\phi^4$ field theory in $1+1$ dimensions. The distribution function, kink density, and correlation function are determined...

Shock Fluctuations in the Two-Dimensional Asymmetric Simple Exclusion Process (1992)

Francis J. Alexander, Zheming Cheng, Steven A. Janowsky, Joel L. Lebowitz

We study via computer simulations (using various serial and parallel updating techniques) the time evolution of shocks, particularly the shock width oe(t), in several versions of the two-dimensional...

Integer Lattice Gases

Bruce Boghosian, Jeffrey Yepez, Francis J. Alexander, Norman H. Margolus

We generalize the hydrodynamic lattice gas model to include arbitrary numbers of particles moving in each lattice direction. For this generalization we derive the equilibrium distribution function...