Hadamard Hypercubes

Although Hadamard matrices have been investigated since the nineteenth century, relatively little is known about their higher-dimensional analogues. In this paper, we introduce two constructions of Hadamard hypercubes. The first construction is derived from conference matrices, while the second is recursive, combining Hadamard matrices (and hypercubes) of smaller order with Latin hypercubes. The former approach draws on the theory of association schemes on triples, whereas the latter yields applications to the construction of higher-dimensional symmetric designs.