news

2025-06-03
new constructions of eight-dimensional non-affine families of complex Hadamard matrices [181] by Tuomo Valtonen (soon to be added to Catalog)

2023-06-03
new construction of generalized Hadamard matrices over *-rings [176]
2023-02-27
new method to generate (complex) Hadamard matrices is described in the section containing various constructions
2023-02-15
an (informal) Appendix to the Catalog is presented; it contains several additional information about (complex) Hadamard matrices, their characteristics and special subsets

2018-09-04
new definition of robust Hadamard matrix [167]
2018-09-03
three exemplary representatives of isolated Butson type matrices $L_{12}^{(0)}$ $\in BH(12,6)$, $L_{16}^{(0)}$ $\in BH(16,4)$ and oversized $L_{21}^{(0)}$ $\in BH(21,3)$ taken from the Butson Home by P. Lampio, F. Szöllősi and P. Östergård [164]
2018-01-01
new non-affine family $T_8^{(1)}$ of complex Hadamard matrices of size $8$ containing two Butson matrices $B_{8A}$ and $B_{8B}$ from $BH(8,20)$ [165]

2017-12-12
new Butson type matrix $L_{14}^{(2)}$ found by P. Lampio, F. Szöllősi and P. Östergård [164]
2017-03-01
three new Butson type matrices $M_{13A}$, $M_{13B}$ and $M_{13C}$ found by R. Nicoară, A. LaClair, N. Geist and A. Wintenberg
2017-02-02
complex matrix determinant optimization game - have fun!

2016-06-06
new isolated matrix $A_8^{(0)}$ [165]
2016-06-05
new set of isolated matrices $V_{8\Sigma}^{(0)}$ found by V. Elser in 2011 (private communication)
2016-05-23
new $2$-parameter non-affine family of complex Hadamard matrices $K_9^{(2)}$ found by B. Karlsson [161]

2014-08-18
a set of complex Hadamard matrices $A_{15\Sigma}$ of dimension $15$ found by A. Munemasa and A. Chan

2012-10-13
new definition of a unit weighing matrix being a generalization of the Hadamard one
2012-09-30
new isolated Hadamard matrices $S_9^{(0)}$ and $S_{14}^{(0)}$ found by D. McNulty and S. Weigert [108]

2011-09-17
new circulant-core matrices found by F. Szöllősi: $Q_7^{(0)}$ and $Q_{11\Sigma}^{(0)}$
2011-07-16
extension of existing $2$-parameter family of M. Petrescu $P_{13}^{(4)}$ up to $4$-dimensional one by F. Szöllősi
2011-05-15
a set of isolated matrices $L_{14\Sigma}^{(0)}$ found by P. Lampio

2008-10-20
new families: $D_{8}^{(4)}$, $D_{10\Sigma}^{(7)}$ and $D_{12\Sigma}^{(9)}$ by P. Diţă [103]
2008-10-13
preprint by A. Skinner et al. in which the existence of a four dimensional Fourier family of order six is claimed
2008-10-02
new two dimensional non-affine family $X_6^{(2)}$ found by F. Szöllősi

2007-10-14
two new Butson type matrices $X_{10}^{(0)}$ and $X_{12}$ found by T. Banica and J.-M. Schlenker [1]
2007-09-06
new definition of quaternion Hadamard matrix [9]

2006-12-28
new family $M_6^{(1)}$ found by M. Matolcsi and F. Szöllősi
2006-12-28
scripts in Matlab and Mathematica
2006-11-05
constructions of complex Hadamard matrices
2006-10-24
new family $H_{12}^{(7)}$ found by F. Szöllősi [25]
2006-10-01
new matrices: $N_9^{(0)}$, $B_9^{(0)}$, $N_{10A}^{(0)}$ and $N_{11B}^{(0)}$ found by K. Beauchamp and R. Nicoară [3]
2006-09-30
new families: $D_{10}^{(3)}$ and $D_{14}^{(5)}$ found by F. Szöllősi [25]
2006-06-30
catalogue of Butson type matrices (currently merged with all other matrices)
2006-06-12
new families: $S_8^{(4)}$, $S_{12}^{(5)}$ and $S_{16}^{(11)}$ found by M. Matolcsi et al. [34]
2006-05-20
new non-affine family $B_6^{(1)}$ found by R. Nicoară and K. Beauchamp [3]
2006-01-04
kick-off! - v.2006.05.04