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Related papers: Hadamard

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Hadamard matrices are square $n\times n$ matrices whose entries are ones and minus ones and whose rows are orthogonal to each other with respect to the standard scalar product in $\Bbb R^n$. Each Hadamard matrix can be transformed to a…

Combinatorics · Mathematics 2021-05-05 Ruslan Sharipov

We introduce the CpMackeyFunctors package for Macaulay2, which allows for computations with Mackey functors over a cyclic group of prime order.

Algebraic Topology · Mathematics 2025-09-09 Thomas Brazelton , David Chan , Benjamin Mudrak , Ben Spitz , Chase Vogeli , Chenglu Wang , Michael R. Zeng , Sasha Zotine

A Generalised Hadamard Transform for multi-phase or multilevel signals is introduced, which includes the Fourier, Generalised, Discrete Fourier, Walsh-Hadamard and Reverse Jacket Transforms. The jacket construction is formalised and shown…

Information Theory · Computer Science 2016-11-17 K. J. Horadam

This article introduces HODLR2D, a new hierarchical low-rank representation for a class of dense matrices arising out of $N$ body problems in two dimensions. Using this new hierarchical framework, we propose a new fast matrix-vector product…

Numerical Analysis · Mathematics 2022-04-13 V A Kandappan , Vaishnavi Gujjula , Sivaram Ambikasaran

For a given selection of rows and columns from a Fourier matrix, we give a number of tests for whether the resulting submatrix is Hadamard based on the primitive sets of those rows and columns. In particular, we demonstrate that whether a…

Rings and Algebras · Mathematics 2021-02-03 John E. Herr , Troy M. Wiegand

We present the $\textit{NumericalImplicitization}$ package for $\textit{Macaulay2}$, which allows for user-friendly computation of the invariants of the image of a polynomial map, such as dimension, degree, and Hilbert function values. This…

Algebraic Geometry · Mathematics 2019-10-16 Justin Chen , Joe Kileel

A quick way to compute generating functions related to Pell-Padovan tetranacci numbers and classical sequences of recursions of order two is provided. Eight special instances can be computed at once.

Combinatorics · Mathematics 2026-03-05 Helmut Prodinger

A new series expansion for the the Airy function is presented here that stems from the method of steepest descents and can be related to the Hadamard expansions as presented in prevous works cited in the manuscript, and which is convergent…

Classical Analysis and ODEs · Mathematics 2024-06-06 Jose Luis Alvarez-Perez

We study a bilinear multiplication rule on 2x2 matrices which is intermediate between the ordinary matrix product and the Hadamard matrix product, and we relate this to the hyperbolic motion group of the plane.

Mathematical Physics · Physics 2020-06-22 Linus Kramer , Peter Kramer , Vladimir Man'ko

In [7] the authors have introduced a new construction using the Hadamard product to present star configurations of codimension $ c $ of $\mathbb{P}^n$ and which they called Hadamard star configurations. In this paper, we introduce a more…

Algebraic Geometry · Mathematics 2019-12-24 Iman Bahmani Jafarloo , Gabriele Calussi

We characterize integral homology classes of the product of two projective planes which are representable by a subvariety.

Algebraic Geometry · Mathematics 2014-06-03 June Huh

We introduce the Hadamard full propelinear codes that factorize as direct product of groups such that their associated group is $C_{2t}\times C_2$. We study the rank, the dimension of the kernel, and the structure of these codes. For…

Combinatorics · Mathematics 2019-02-19 Ivan Bailera , Joaquim Borges , Josep Rifà

Given a collection of line bundles on a complete toric variety, the Macaulay2 package QuiversToricVarieties contains functions to construct its quiver of sections and check whether the collection is strong exceptional. It contains a…

Algebraic Geometry · Mathematics 2015-01-27 Nathan Prabhu-Naik

We computationally resolve an open problem concerning the expressibility of $4 \times 4$ full-rank matrices as Hadamard products of two rank-2 matrices. Through exhaustive search over $\mathbb{F}_2$, we identify 5,304 counterexamples among…

Rings and Algebras · Mathematics 2025-08-22 Igor Rivin

This paper examines the use of Lie group and Lie Algebra theory to construct the geometry of pairwise comparisons matrices. The Hadamard product (also known as coordinatewise, coordinate-wise, elementwise, or element-wise product) is…

General Mathematics · Mathematics 2021-05-24 W. W. Koczkodaj , V. W. Marek , Y. Yayli

We highlight some features of the SimplicialComplexes package in Macaulay2.

Commutative Algebra · Mathematics 2023-08-30 Ben Hersey , Gregory G. Smith , Alexandre Zotine

In this paper, firstly, we define the Qq-generating matrix for bi-periodic Fibonacci polynomial. And we give nth power, determinant and some properties of the bi-periodic Fibonacci polynomial by considering this matrix representation. Also,…

Number Theory · Mathematics 2019-04-19 A. Coskun , N. Taskara

We show that any two Hadamard subfactors arising from a pair of distinct complex Hadamard matrices of order 3 are either equal or conjugate by a unitary in the relative commutant of their intersection. Moreover, when the Hadamard subfactors…

Operator Algebras · Mathematics 2025-09-17 Keshab Chandra Bakshi , Satyajit Guin , Guruprasad

In this paper, we compute the homology group and cohomology algebra of various polyhedral product objects uniformly from the point of view of diagonal tensor product. As applications, we introduce the polyhedral product method into…

Algebraic Topology · Mathematics 2018-04-24 Qibing Zheng

To any complex Hadamard matrix H one associates a spin model commuting square, and therefore a hyperfinite subfactor. The standard invariant of this subfactor captures certain "group-like" symmetries of H. To gain some insight, we compute…

Operator Algebras · Mathematics 2007-05-23 Wes Camp , Remus Nicoara
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