activity
19952011
most citedThe susceptibility of the square lattice Ising model: New developments

91 citations · 261 across the 13 of their papers we have counts for

collaborators

13 papers

math.CO2011★ 9 cited

Maximal determinants and saturated D-optimal designs of orders 19 and 37

Richard P. Brent, William Orrick, Judy-anne Osborn +1

A saturated D-optimal design is a {+1,-1} square matrix of given order with maximal determinant. We search for saturated D-optimal designs of orders 19 and 37, and find that known…

math-ph2006★ 27 cited

Holonomy of the Ising model form factors

S. Boukraa, S. Hassani, J. -M. Maillard +3

We study the Ising model two-point diagonal correlation function by presenting an exponential and form factor expansion in an integral representation which differs from t…

math.CO2005

On the enumeration of some D-optimal designs

William P. Orrick

Two matrices with elements taken from the set {-1,1} are Hadamard equivalent if one can be converted into the other by a sequence of permutations of rows and columns, and negations…

math.CO2005

Switching operations for Hadamard matrices

William P. Orrick

We define several operations that switch substructures of Hadamard matrices thereby producing new, generally inequivalent, Hadamard matrices. These operations have application to t…

math.CO2004

The maximal {-1,1}-determinant of order 15

William P. Orrick

We study the question of finding the maximal determinant of matrices of odd order with entries {-1,1}. The most general upper bound on the maximal determinant, due to Barba, can on…

math.CO2003★ 2 cited

Large-determinant sign matrices of order 4k+1

William P. Orrick, Bruce Solomon

The Hadamard maximal determinant problem asks for the largest n-by-n determinant with entries in {+1,-1}. When n is congruent to 1 (mod 4), the maximal excess construction of Farma…