✦ LIBER ✦

Conjectures about Hadamard matrices

✍ Scribed by Jay H. Beder

Publisher: Elsevier Science
Year: 1998
Tongue: English
Weight: 75 KB
Volume: 72
Category: Article
ISSN: 0378-3758
DOI: 10.1016/s0378-3758(98)00020-2

No coin nor oath required. For personal study only.

✦ Synopsis

The purpose of this paper is to discuss some conjectures related to the construction of Hadamard matrices. We review the results of a computer experiment concerning the extendability of row-Hadamard matrices, generating new conjectures and giving a counterexample to one suggested by Vijayan. An earlier computer investigation by Hall is discussed. We also connect the standard conjectures on the existence of real and generalized Hadamard matrices to the ramiÿcation of primes in cyclotomic extensions.

📜 SIMILAR VOLUMES

Hadamard matrices of small order and Yan

Hadamard matrices of small order and Yang conjecture

✍ Dragomir Ž. Ðoković 📂 Article 📅 2010 🏛 John Wiley and Sons 🌐 English ⚖ 79 KB 👁 1 views

## Abstract We show that 138 odd values of __n__<10000 for which a Hadamard matrix of order 4__n__ exists have been overlooked in the recent handbook of combinatorial designs. There are four additional odd __n__=191, 5767, 7081, 8249 in that range for which Hadamard matrices of order 4__n__ exist.

A conjecture concerning the Hadamard pro

A conjecture concerning the Hadamard product of inverses of M-matrices

✍ M. Neumann 📂 Article 📅 1998 🏛 Elsevier Science 🌐 English ⚖ 804 KB

We conjecture that for an n x n matrix A which is an inverse of an M-matrix, the Hadamard product A o A is also an inverse of an M-matrix. We have checked this conjecture without failure on many many examples. But here we show that for quite a few well known classes of inverses of M-matrices, the co

A conjecture about lower multiexponent o

A conjecture about lower multiexponent of primitive matrices

✍ Bolian Liu; Fengying Huang 📂 Article 📅 2008 🏛 Elsevier Science 🌐 English ⚖ 304 KB

In this paper the conjecture on kth lower multiexponent of primitive matrices proposed by R.A.

Deciding Hadamard equivalence of Hadamar

Deciding Hadamard equivalence of Hadamard matrices

✍ Charles J. Colbourn; Marlene J. Colbourn 📂 Article 📅 1981 🏛 Springer Netherlands 🌐 English ⚖ 164 KB

Rectangular Hadamard matrices

✍ Kishore Sinha 📂 Article 📅 1988 🏛 Elsevier Science 🌐 English ⚖ 79 KB

Proof of a conjecture concerning the Had

Proof of a conjecture concerning the Hadamard powers of inverse M-matrices

✍ Shencan Chen 📂 Article 📅 2007 🏛 Elsevier Science 🌐 English ⚖ 108 KB