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The Hadamard decomposition is a powerful technique for data analysis and matrix compression, which decomposes a given matrix into the element-wise product of two or more low-rank matrices. In this paper, we develop an efficient algorithm to…

Machine Learning · Computer Science 2025-04-23 Samuel Wertz , Arnaud Vandaele , Nicolas Gillis

We introduce qustochastic matrices as the bistochastic matrices arising from quaternionic unitary matrices by replacing each entry with the square of its norm. This is the quaternionic analogue of the unistochastic matrices studied by…

Mathematical Physics · Physics 2009-03-18 Oleg Chterental , Dragomir Z. Djokovic

A new, two-parameter, nonaffine family of complex Hadamard matrices of order 6 is reported. It interpolates between the two Fourier families, and contains as one-parameter subfamilies the Dita family, a symmetric family and an almost (up to…

Mathematical Physics · Physics 2015-05-13 Bengt R. Karlsson

A new construction of complex Hadamard matrices of composite order d=pq, with primes p,q, is presented which is based on pairs of mutually unbiased bases containing only product states. For product dimensions d < 100, we illustrate the…

Mathematical Physics · Physics 2012-12-05 Daniel McNulty , Stefan Weigert

We compute approximate solutions to inverse problems for determining parameters in differential equation models with stochastic data on output quantities. The formulation of the problem and modeling framework define a solution as a…

Numerical Analysis · Mathematics 2014-07-16 Troy Butler , Don Estep , Simon Tavener , Timothy Wildey , Clint Dawson , Lindley Graham

The algebraic relations between the principal minors of an $n\times n$ matrix are somewhat mysterious, see e.g. [lin-sturmfels]. We show, however, that by adding in certain \emph{almost} principal minors, the relations are generated by a…

Combinatorics · Mathematics 2014-10-01 Richard Kenyon , Robin Pemantle

For each pair of complex symmetric matrices $(A,B)$ we provide a normal form with a minimal number of independent parameters, to which all pairs of complex symmetric matrices $(\widetilde{A},\widetilde{B})$, close to $(A,B)$ can be reduced…

Representation Theory · Mathematics 2018-05-31 Andrii Dmytryshyn

In our article we consider some algebraical methods which may be useful in some inverse spectral problems. The reconstraction of the matrix from its minors is considered.

Commutative Algebra · Mathematics 2007-05-23 A. V. Mouftakhov

Order parameters based on spherical harmonics and Fourier coefficients already play a significant role in condensed matter research in the context of systems of spherical or point particles. Here, we extend these types of order parameter to…

Soft Condensed Matter · Physics 2010-12-22 Aaron S. Keys , Christopher R. Iacovella , Sharon C. Glotzer

Diagonalization, or eigenvalue decomposition, is very useful in many areas of applied mathematics, including signal processing and quantum physics. Matrix decomposition is also a useful tool for approximating matrices as the product of a…

Spectral Theory · Mathematics 2016-06-07 Théo Trouillon , Christopher R. Dance , Éric Gaussier , Guillaume Bouchard

In this paper we have discussed different possible orthogonalities in matrices, namely orthogonal, quasi-orthogonal, semi-orthogonal and non-orthogonal matrices including completely positive matrices, while giving some of their…

Discrete Mathematics · Computer Science 2007-05-23 R. N. Mohan

Hadamard matrices are $(-1, +1)$ square matrices with mutually orthogonal rows. The Hadamard conjecture states that Hadamard matrices of order $n$ exist whenever $n$ is $1$, $2$, or a multiple of $4$. However, no construction is known that…

Combinatorics · Mathematics 2023-06-30 Matteo Cati , Dmitrii V. Pasechnik

We study a class of holomorphic matrix models. The integrals are taken over middle dimensional cycles in the space of complex square matrices. As the size of the matrices tends to infinity, the distribution of eigenvalues is given by a…

High Energy Physics - Theory · Physics 2009-11-10 Giovanni Felder , Roman Riser

In this article, a series of Hadamard matrix has been developed using some block matrices with the help of skew Hadamard matrix. Basically an internal structure of skew Hadamard matrix has been changed with some block matrices using…

Combinatorics · Mathematics 2021-08-19 Shipra Kumari , Hrishikesh Mahato

Applications in quantum information theory and quantum tomography have raised current interest in complex Hadamard matrices. In this note we investigate the connection between tiling Abelian groups and constructions of complex Hadamard…

Quantum Physics · Physics 2007-05-23 Máté Matolcsi , Júlia Réffy , Ferenc Szöllősi

The algebra of invariants of d-tuples of n x n skew-symmetric matrices under the action of the orthogonal group by simultaneous conjugation is considered over an infinite field of characteristic different from two. For n=3 and d>0 a minimal…

Representation Theory · Mathematics 2012-07-24 A. A. Lopatin

We present a matrix-based algorithm for deciding if the parametrization of a curve or a surface is invertible or not, and for computing the inverse of the parametrization if it exists.

Commutative Algebra · Mathematics 2007-05-23 Carlos D'Andrea , Laurent Buse

The paper discusses progress in understanding statistical properties of complex eigenvalues (and corresponding eigenvectors) of weakly non-unitary and non-Hermitian random matrices. Ensembles of this type emerge in various physical…

Chaotic Dynamics · Physics 2009-11-07 Yan V Fyodorov , H. -J Sommers

A superposition of a matrix ensemble refers to the ensemble constructed from two independent copies of the original, while a decimation refers to the formation of a new ensemble by observing only every second eigenvalue. In the cases of the…

Mathematical Physics · Physics 2007-05-23 Peter J. Forrester , Eric M. Rains

The non-linear transformations incurred by the rays in an optical system can be suitably described by matrices to any desired order of approximation. In systems composed of uniform refractive index elements, each individual ray refraction…

Optics · Physics 2009-11-10 Jose B. Almeida