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Asher Baram

Publications and source records attributed to Asher Baram.

4 recordsLinked to original sources

Estimation of critical exponents from the cluster coefficients: Application to hard spheres

For a large class of repulsive interaction models, the Mayer cluster integrals can be transformed into a tridiagonal symmetric matrix, whose elements converge to a constant with a 1/n^2 correction. We find exact expressions, in terms of these correction terms, for the two critical exponents describing the density near the two singular termination points of the fluid phase. We apply the method to the hard-spheres model and find that the metastable fluid phase terminates at rho_t=0.751(5). The density near the transition is given by (rho_t-rho)~(z_t-z)^sigma', where the critical exponent is predicted to be sigma'=0.0877(25). The termination density is close to the observed glass transition, and thus the above critical behavior is expected to characterize the onset of glassy behavior in hard spheres.

cond-mat.stat-mech

Analysis of the ordering transition of hard disks through the Mayer cluster expansion

The available virial coefficients for the 2D hard disks model are transformed into a matrix representation of the thermodynamic potentials, which allows for an accurate description of the whole fluid phase, up to the phase transition. We find that the fluid phase terminates at the transition point, supporting the Kosterlitz-Thouless-Halperin-Nelson-Young picture of a second order phase transition into a Hexatic phase. The density and pressure at the transition are calculated from the available first ten virial coefficients, and are found to be in excellent agreement with recent Monte-Carlo calculations. Finally, we calculate the equation of state in the critical region.

cond-mat.stat-mech

Diffusional Relaxation in Random Sequential Deposition

The effect of diffusional relaxation on the random sequential deposition process is studied in the limit of fast deposition. Expression for the coverage as a function of time are analytically derived for both the short-time and long-time regimes. These results are tested and compared with numerical simulations.

cond-mat.stat-mech

Calculation of the Density of States Using Discrete Variable Representation and Toeplitz Matrices

A direct and exact method for calculating the density of states for systems with localized potentials is presented. The method is based on explicit inversion of the operator $E-H$. The operator is written in the discrete variable representation of the Hamiltonian, and the Toeplitz property of the asymptotic part of the obtained {\it infinite} matrix is used. Thus, the problem is reduced to the inversion of a {\it finite} matrix.

cond-mat