H-2-reducible complex Hadamard matrices of order 6

• Complex Hadamard matrices H of order 6 are characterized in a novel manner, according to the presence/absence of order 2 Hadamard submatrices. It is shown that if there exists one such submatrix. H is equivalent to a Hadamard matrix where all the nine submatrices are Hadamard. The ensuing subset of H-2-reducible complex Hadamard matrices is more general than might be thought, and, significantly, includes all the up till now described (one- and two-parameter) families of order 6. A known, isolated matrix, and most numerically generated matrices, fall outside the subset.

Subject headings

NATURVETENSKAP  -- Matematik (hsv//swe)

NATURAL SCIENCES  -- Mathematics (hsv//eng)

Keyword

Complex Hadamard matrix

Six dimensions

MATHEMATICS

MATEMATIK

Publication and Content Type

ref (subject category)

art (subject category)