Switching Operations for Hadamard Matrices

We define several operations that switch substructures of Hadamard matrices, thereby producing new, generally inequivalent, Hadamard matrices. These operations have application to the enumeration and classification of Hadamard matrices. To illustrate their power, we use them to greatly improve the lower bounds on the number of equivalence classes of Hadamard matrices in orders 32 and 36 to 3,578,006 and 18,292,717.

• Publication year

  2005

• Venue

  SIAM Journal on Discrete Mathematics

• Publication date

  2005-07-25

• Fields of study

  Mathematics, Computer Science

• Identifiers
  DOI 10.1137/050641727arXiv math/0507515
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar

• No claims are published for this paper.

• No concepts are published for this paper.

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