Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 8 of 8

Full-Text Articles in Physical Sciences and Mathematics

Efficiency Of Competitions, E. Ben-Naim, N.W. Hengartner Aug 2007

Efficiency Of Competitions, E. Ben-Naim, N.W. Hengartner

Eli Ben-Naim

League competition is investigated using random processes and scaling techniques. In our model, a weak team can upset a strong team with a fixed probability. Teams play an equal number of head-to-head matches and the team with the largest number of wins is declared to be the champion. The total number of games needed for the best team to win the championship with high certainty, T, grows as the cube of the number of teams, N, i.e., T ~ N^3. This number can be substantially reduced using preliminary rounds where teams play a small number of games and subsequently, only …


Kinetic Theory Of Random Graphs: From Paths To Cycles, E. Ben-Naim, P.L. Krapivsky Dec 2005

Kinetic Theory Of Random Graphs: From Paths To Cycles, E. Ben-Naim, P.L. Krapivsky

Eli Ben-Naim

Structural properties of evolving random graphs are investigated. Treating linking as a dynamic aggregation process, rate equations for the distribution of node to node distances (paths) and of cycles are formulated and solved analytically. At the gelation point, the typical length of paths and cycles, l, scales with the component size k as l ~ k^{1/2}. Dynamic and finite-size scaling laws for the behavior at and near the gelation point are obtained. Finite-size scaling laws are verified using numerical simulations.


The Inelastic Maxwell Model, E. Ben-Naim, P.L. Krapivsky Jul 2003

The Inelastic Maxwell Model, E. Ben-Naim, P.L. Krapivsky

Eli Ben-Naim

Dynamics of inelastic gases are studied within the framework of random collision processes. The corresponding Boltzmann equation with uniform collision rates is solved analytically for gases, impurities, and mixtures. Generally, the energy dissipation leads to a significant departure from the elastic case. Specifically, the velocity distributions have overpopulated high energy tails and different velocity components are correlated. In the freely cooling case, the velocity distribution develops an algebraic high-energy tail, with an exponent that depends sensitively on the dimension and the degree of dissipation. Moments of the velocity distribution exhibit multiscaling asymptotic behavior, and the autocorrelation function decays algebraically with …


Knots And Random Walks In Vibrated Granular Chains, E. Ben-Naim, Z.A. Daya, P. Vorobieff, R.E. Ecke Feb 2001

Knots And Random Walks In Vibrated Granular Chains, E. Ben-Naim, Z.A. Daya, P. Vorobieff, R.E. Ecke

Eli Ben-Naim

We study experimentally statistical properties of the opening times of knots in vertically vibrated granular chains. Our measurements are in good qualitative and quantitative agreement with a theoretical model involving three random walks interacting via hard core exclusion in one spatial dimension. In particular, the knot survival probability follows a universal scaling function which is independent of the chain length, with a corresponding diffusive characteristic time scale. Both the large-exit-time and the small-exit-time tails of the distribution are suppressed exponentially, and the corresponding decay coefficients are in excellent agreement with the theoretical values.


Shock-Like Dynamics Of Inelastic Gases, E. Ben-Naim, S.Y. Chen, G.D. Doolen Nov 1999

Shock-Like Dynamics Of Inelastic Gases, E. Ben-Naim, S.Y. Chen, G.D. Doolen

Eli Ben-Naim

No abstract provided.


Towards Granular Hydrodynamics In Two-Dimensions, E.L. Grossman, T. Zhou, E. Ben-Naim Apr 1997

Towards Granular Hydrodynamics In Two-Dimensions, E.L. Grossman, T. Zhou, E. Ben-Naim

Eli Ben-Naim

We study steady-state properties of inelastic gases in two-dimensions in the presence of an energy source. We generalize previous hydrodynamic treatments to situations where high and low density regions coexist. The theoretical predictions compare well with numerical simulations in the nearly elastic limit. It is also seen that the system can achieve a nonequilibrium steady-state with asymmetric velocity distributions, and we discuss the conditions under which such situations occur.


Coarsening And Persistence In The Voter Model, E. Ben-Naim, L. Frachebourg, P.L. Krapivsky Dec 1996

Coarsening And Persistence In The Voter Model, E. Ben-Naim, L. Frachebourg, P.L. Krapivsky

Eli Ben-Naim

No abstract provided.


Kinetics Of Clustering In Traffic Flows, E. Ben-Naim, P. L. Krapivsky, S. Redner Dec 1994

Kinetics Of Clustering In Traffic Flows, E. Ben-Naim, P. L. Krapivsky, S. Redner

Eli Ben-Naim

We study a simple aggregation model that mimics the clustering of traffic on a one-lane roadway. In this model, each ``car'' moves ballistically at its initial velocity until it overtakes the preceding car or cluster. After this encounter, the incident car assumes the velocity of the cluster which it has just joined. The properties of the initial distribution of velocities in the small velocity limit control the long-time properties of the aggregation process. For an initial velocity distribution with a power-law tail at small velocities, $\pvim$ as $v \to 0$, a simple scaling argument shows that the average cluster size …