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Related papers: Block-Circulant Complex Hadamard Matrices

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Assume that $H$ is a circulant Hadamard matrix of order $n\geq 4$. We consider an appropriate stochastic matrix $S$ of order $n$ depending on $H$. This allows us to prove that $n = 4$. Thus, there are only $10$ circulant Hadamard matrices.

Number Theory · Mathematics 2024-05-24 Luis H. Gallardo

In this work, we propose an optimization approach for constructing various classes of circulant combinatorial designs that can be defined in terms of autocorrelations. The problem is formulated as a so-called feasibility problem having…

Combinatorics · Mathematics 2018-08-13 Francisco J. Aragón Artacho , Rubén Campoy , Ilias Kotsireas , Matthew K. Tam

We study general quantum integrable Hamiltonians linear in a coupling constant and represented by finite NxN real symmetric matrices. The restriction on the coupling dependence leads to a natural notion of nontrivial integrals of motion and…

Other Condensed Matter · Physics 2011-09-13 Haile K. Owusu , Emil A. Yuzbashyan

We study the problem of constructing mutually unbiased bases in dimension six. This approach is based on an efficient numerical method designed to find solutions to the quantum state reconstruction problem in finite dimensions. Our…

Quantum Physics · Physics 2013-04-24 D. Goyeneche

In this paper we give a new construction of parametric families of complex Hadamard matrices of square orders, and connect them to equiangular tight frames. The results presented here generalize some of the recent ideas of Bodmann et al.…

Functional Analysis · Mathematics 2011-04-19 Ferenc Szöllősi

Our main result is the construction of symmetric Hadamard matrices of order q(1 + q) where q is a prime power congruent to 3 mod 8.

Combinatorics · Mathematics 2025-08-26 Dragomir Ž. Djoković

The subject of the present work is the de Rham part of non-commutative Hodge structures on the periodic cyclic homology of differential graded algebras and categories. We discuss explicit formulas for the corresponding connection on the…

Algebraic Geometry · Mathematics 2012-07-25 D. Shklyarov

For positive integers $m$ and $n$, we denote by $\mathrm{BH}(m,n)$ the set of all $H\in M_{n\times n}(\mathbb{C})$ such that $HH^\ast=nI_n$ and each entry of $H$ is an $m$-th root of unity where $H^\ast$ is the adjoint matrix of $H$ and…

Combinatorics · Mathematics 2014-02-28 Kyoung-Tark Kim , Hirasaka Mitsugu , Yoshihiro Mizoguchi

In this paper a variety of issues are discussed, Schur ring, $S$-sets, circulant orbits, decimation operator and Hadamard matrices and their relation between them is shown. Firstly we define the complete $S$-sets. Next, we study the…

Combinatorics · Mathematics 2019-04-12 Ronald Orozco López

MDS matrices play a critical role in the design of diffusion layers for block ciphers and hash functions due to their optimal branch number. Involutory and orthogonal MDS matrices offer additional benefits by allowing identical or nearly…

Cryptography and Security · Computer Science 2026-01-23 Yogesh Kumar , Susanta Samanta , Atul Gaur

A consequent approach is proposed to construct symplectic force-gradient algorithms of arbitrarily high orders in the time step for precise integration of motion in classical and quantum mechanics simulations. Within this approach the basic…

Statistical Mechanics · Physics 2009-11-07 Igor Omelyan , Ihor Mryglod , Reinhard Folk

The hidden Markov model (HMM) is a generative model that treats sequential data under the assumption that each observation is conditioned on the state of a discrete hidden variable that evolves in time as a Markov chain. In this paper, we…

Artificial Intelligence · Computer Science 2011-09-07 Emanuele Coviello , Antoni B. Chan , Gert R. G. Lanckriet

We apply the framework of block-encodings, introduced by Low and Chuang (under the name standard-form), to the study of quantum machine learning algorithms and derive general results that are applicable to a variety of input models,…

Quantum Physics · Physics 2020-02-21 Shantanav Chakraborty , András Gilyén , Stacey Jeffery

We construct a skew-Hadamard matrix of order 1252 = 2(5^4 + 1) using a bordered skew-Hadamard difference family over GF(5^4), with blocks given as unions of cyclotomic classes of order N = 16. This order has been reported as missing in some…

Combinatorics · Mathematics 2026-02-19 Amira Karoui

This paper is concerned with quasi-unbiased Hadamard matrices and weakly unbiased Hadamard matrices, which are generalizations of unbiased Hadamard matrices, equivalently unbiased bases. These matrices are studied from the viewpoint of…

Combinatorics · Mathematics 2015-10-01 Makoto Araya , Masaaki Harada , Sho Suda

Exponential integrators based on contour integral representations lead to powerful numerical solvers for a variety of ODEs, PDEs, and other time-evolution equations. They are embarrassingly parallelizable and lead to global-in-time…

Numerical Analysis · Mathematics 2024-11-15 Andrew Horning , Adam R. Gerlach

We introduce the concept of n-OU and n-OO matrix sets, a collection of n mutually-orthogonal unitary and real orthogonal matrices under Hilbert-Schmidt inner product. We give a detailed characterization of order-three n-OO matrix sets under…

Quantum Physics · Physics 2025-10-28 Zhiwei Song , Lin Chen , Saiqi Liu

As an approximate nearest neighbor search technique, hashing has been widely applied in large-scale image retrieval due to its excellent efficiency. Most supervised deep hashing methods have similar loss designs with embedding learning,…

Computer Vision and Pattern Recognition · Computer Science 2019-10-22 Shen Chen , Liujuan Cao , Mingbao Lin , Yan Wang , Xiaoshuai Sun , Chenglin Wu , Jingfei Qiu , Rongrong Ji

We describe combinatorial properties of the defining row of a circulant Hadamard matrix by exploiting its orthogonality to subsequent rows, and show how to exclude several particular forms of these matrices.

Combinatorics · Mathematics 2024-06-18 Luis H. Gallardo , Olivier Rahavandrainy , Reinhardt. Euler

In this paper three Schur ring are discussed, namenly: Hamming, circulant orbists and decimated circulant orbits Schur ring. By using autocorrelation function and the run structure of binary sequences we proof the relation between this…

Combinatorics · Mathematics 2018-07-31 Ronald Orozco López