arXiv subjects

J. W. Essam

Publications and source records attributed to J. W. Essam.

5 recordsLinked to original sources

arXiv2014

Resistance between two nodes in general position on an $m\times n$ fan network

The resistance between two nodes in general position on a fan network with n radial lines and m transverse lines is determined. Also a similar result of Izmailian, Kenna and Wu [7] for an $m\times n$ cobweb network is reproduced but the method used here is significantly different. It avoids the use of the Kirchhoff matrix, requires the solution of just one instead of two eigenvalue problems and results directly in only a single summation. Further the current distribution is given explicitly as a biproduct of the method. The method is the same as that used by Tan, Zhou and Yang [10] to find the cobweb resistance between center and perimeter for $1\le m\le3$ and general $n$. Proof of their conjecture for general $m$ is discussed.

cond-mat.stat-mech↗

arXiv2014

The two-point resistance of a cobweb with a superconducting boundary

We consider the problem of two-point resistance on an m x n cobweb network with a superconducting boundary, which is topologically equivalent to a geographic globe. We deduce a concise formula for the resistance between any two nodes on the globe using a method of direct summation pioneered by one of us [Z. Z. Tan, et al, J. Phys. A 46, 195202 (2013)]. This method contrasts the Laplacian matrix approach which is difficult to apply to the geometry of a globe. Our analysis gives the result directly as a single summation.

cond-mat.stat-mech↗

arXiv2013

Proof and extension of the resistance formula for an m x n cobweb network conjectured by Tan, Zhou and Yang

An m x n cobweb network consists of n radial lines emanating from a center and connected by $m$ concentric n-sided polygons. A conjecture of Tan, Zhou and Yang for the resistance from center to perimeter of the cobweb is proved by extending the method used by the above authors to derive formulae for m = 1, 2 and 3 and general n. The resistance of an m x (s+t+1) fan network from the apex to a point on the boundary distant s from the corner is also found.

cond-mat.stat-mech↗

arXiv2008

The exact evaluation of the corner-to-corner resistance of an M x N resistor network: Asymptotic expansion

We study the corner-to-corner resistance of an M x N resistor network with resistors r and s in the two spatial directions, and obtain an asymptotic expansion of its exact expression for large M and N. For M = N, r = s =1, our result is R_{NxN} = (4/pi) log N + 0.077318 + 0.266070/N^2 - 0.534779/N^4 + O(1/N^6).

cond-mat.stat-mech↗

arXiv2000

From the Bethe Ansatz to the Gessel-Viennot Theorem

We state and prove several theorems that demonstrate how the coordinate Bethe Ansatz for the eigenvectors of suitable transfer matrices of a generalised inhomogeneous five-vertex model on the square lattice, given certain conditions hold, is equivalent to the Gessel-Viennot determinant for the number of configurations of $N$ non-intersecting directed lattice paths, or vicious walkers, with various boundary conditions. Our theorems are sufficiently general to allow generalisation to any regular planar lattice.

math.CO↗