We constructed 480 inequivalent Hadamard matrices with Hall sets of order 28 in Kimura (1988) and Kimura and Ohmori (1987). These matrices were classified by K-matrices and K-boxes associated with Hadamard matrices. In this paper we introduce some order on subsets of equivalence classes. By choosing
Classification of Hadamard matrices of order 28
โ Scribed by Hiroshi Kimura
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 489 KB
- Volume
- 133
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
We constructed all inequivalent Hadamard matrices with Hall sets of order 28 and classified by K-matrices associated with Hadamard matrices except five matrices in our earlier work (Kimura, 1988) (see also Kimura, to appear;Kimura and Ohmori, 1987). In this paper we prove that Hadamard matrices with the trivial K-matrix are equivalent to the Paley matrix defined by the squares in GF (27). By this theorem we get a complete classification of Hadamard matrices of order 28 and we have inequivalent Hadamard matrices of order 28.
๐ SIMILAR VOLUMES
## Abstract All equivalence classes of Hadamard matrices of order at most 28 have been found by 1994. Order 32 is where a combinatorial explosion occurs on the number of Hadamard matrices. We find all equivalence classes of Hadamard matrices of order 32 which are of certain types. It turns out that