English

New constructions of Hadamard matrices

Combinatorics 2019-07-16 v2

Abstract

In this paper, we obtain a number of new infinite families of Hadamard matrices. Our constructions are based on four new constructions of difference families with four or eight blocks. By applying the Wallis-Whiteman array or the Kharaghani array to the difference families constructed, we obtain new Hadamard matrices of order 4(uv+1)4(uv+1) for u=2u=2 and vΦ1Φ2Φ3Φ4v\in \Phi_1\cup \Phi_2 \cup \Phi_3 \cup \Phi_4; and for u{3,5}u\in \{3,5\} and vΦ1Φ2Φ3v\in \Phi_1\cup \Phi_2 \cup \Phi_3. Here, Φ1={q2:q1(mod4)\mboxisaprimepower}\Phi_1=\{q^2:q\equiv 1\pmod{4}\mbox{ is a prime power}\}, Φ2={n4N:n1(mod2)}{9n4N:n1(mod2)}\Phi_2=\{n^4\in \mathbb{N}:n\equiv 1\pmod{2}\} \cup \{9n^4\in \mathbb{N}:n\equiv 1\pmod{2}\}, Φ3={5}\Phi_3=\{5\} and Φ4={13,37}\Phi_4=\{13,37\}. Moreover, our construction also yields new Hadamard matrices of order 8(uv+1)8(uv+1) for any uΦ1Φ2u\in \Phi_1\cup \Phi_2 and vΦ1Φ2Φ3v\in \Phi_1\cup \Phi_2 \cup \Phi_3.

Keywords

Cite

@article{arxiv.1809.05253,
  title  = {New constructions of Hadamard matrices},
  author = {Ka Hin Leung and Koji Momihara},
  journal= {arXiv preprint arXiv:1809.05253},
  year   = {2019}
}

Comments

22 pages, revised version

R2 v1 2026-06-23T04:06:12.425Z