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Related papers: Hadamard Star Configurations

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It is shown that a (curved) projective structure on a smooth manifold determines on the Poisson algebra of smooth, fiberwise-polynomial functions on the cotangent bundle a one-parameter family of graded star products. For a particular value…

Differential Geometry · Mathematics 2013-06-25 Daniel J. F. Fox

A complex Hadamard matrix is a square matrix H with complex entries of absolute value 1 satisfying $HH^*= nI$, where $*$ stands for the Hermitian transpose and I is the identity matrix of order $n$. In this paper, we first determine the…

Combinatorics · Mathematics 2017-10-20 Takuya Ikuta , Akihiro Munemasa

We describe a series of experiments involving the creation of cylindrical packings of star-shaped particles, and an exploration of the stability of these packings. The stars cover a broad range of arm sizes and frictional properties. We…

Soft Condensed Matter · Physics 2020-02-25 Yuchen Zhao , Kevin Liu , Matthew Zheng , Jonathan Barés , Karola Dierichs , Achim Menges , Robert P. Behringer

We describe a construction of three-dimensional Hadamard matrices of even order $v$ such that $v-1$ is a prime power. The construction covers infinitely many orders for which the existence was previously open.

Combinatorics · Mathematics 2025-09-30 Vedran Krčadinac , Mario Osvin Pavčević , Kristijan Tabak

We study the so called hybrid stars, which are hadronic stars that contain a core of deconfined quarks. For this purpose, we make use of an extended version of the SU(3) chiral model. Within this approach, the degrees of freedom change…

High Energy Physics - Phenomenology · Physics 2012-10-17 V. Dexheimer , S. Schramm , J. Stone

A set partition of $[n] := \{1, 2, \dots, n \}$ is called {\em $r$-Stirling} if the numbers $1, 2, \dots, r$ belong to distinct blocks. Haglund, Rhoades, and Shimozono constructed graded ring $R_{n,k}$ depending on two positive integers $k…

Combinatorics · Mathematics 2019-07-04 Brendon Rhoades , Andrew Timothy Wilson

Let $n$ points be in crescent configurations in $\mathbb{R}^d$ if they lie in general position in $\mathbb{R}^d$ and determine $n-1$ distinct distances, such that for every $1 \leq i \leq n-1$ there is a distance that occurs exactly $i$…

Combinatorics · Mathematics 2019-01-14 Rebecca F. Durst , Max Hlavacek , Chi Huynh , Steven J. Miller , Eyvindur A. Palsson

Let $X$ be a product of $r$ locally compact Hadamard spaces. In this note we prove that the horospheres in $X$ centered at regular boundary points of $X$ are Lipschitz-$(r-2)$-connected. Using the filling construction by R.~Young in…

Metric Geometry · Mathematics 2015-08-11 Gabriele Link

Consider the set of scalars $\alpha$ for which the $\alpha$th Hadamard power of any $n\times n$ positive semi-definite (p.s.d.) matrix with non-negative entries is p.s.d. It is known that this set is of the form $\{0, 1, \dots, n-3\}\cup…

Classical Analysis and ODEs · Mathematics 2022-06-15 Jnaneshwar Baslingker , Biltu Dan

In this paper we construct star products on a pseudo-K\"ahler manifold $(M,\omega,I)$ using a modification of the Fedosov method based on a different fibrewise product similar to the Wick product on $\mathbb C^n$. In a first step we show…

Quantum Algebra · Mathematics 2009-11-07 Nikolai Neumaier

We analyze the resolved stellar populations of 473 massive star-forming galaxies at 0.7 < z < 1.5, with multi-wavelength broad-band imaging from CANDELS and Halpha surface brightness profiles at the same kiloparsec resolution from 3D-HST.…

We study $n$-dimensional matrices with $\{0,1\}$-entries ($n$-cubes) such that all their $2$-dimensional slices are incidence matrices of symmetric designs. A known construction of these objects obtained from difference sets is generalized…

Combinatorics · Mathematics 2025-09-30 Vedran Krčadinac , Mario Osvin Pavčević , Kristijan Tabak

We introduce a simplified method for calculating the loss function for use in geometric shaping, allowing for the optimisation of high dimensional constellations. We design constellations up to 12D with 4096 points, with gains up to 0.31 dB…

Information Theory · Computer Science 2023-07-12 Kadir Gümüş , Bin Chen , Thomas Bradley , Chigo Okonkwo

We introduce a construction that, given a pair (u,v) of complex Hadamard matrices of the same order, generates infinitely many biunitary matrices of varying (and distinct) orders. As a key application, this framework yields nested sequences…

Operator Algebras · Mathematics 2026-01-16 Keshab Chandra Bakshi , Satyajit Guin , Guruprasad

Taking a novel approach, this paper discuss the structure of compact stars, an important topic in theoretical astrophysics. Adopting the Newtonian gravitation, we solve the hydrostatic equilibrium equation by imposing a simple…

Solar and Stellar Astrophysics · Physics 2014-07-22 Hilario Rodrigues

We construct Hadamard matrices of orders 4x251 = 1004 and 4x631 = 2524, and skew-Hadamard matrices of orders 4x213 = 852 and 4x631 = 2524. As far as we know, such matrices have not been constructed previously. The constructions use the…

Combinatorics · Mathematics 2014-06-13 Dragomir Z. Djokovic , Oleg Golubitsky , Ilias S. Kotsireas

A set is star-shaped if there is a point in the set that can see every other point in the set in the sense that the line-segment connecting the points lies within the set. We show that testing whether a non-empty compact smooth region is…

Computational Geometry · Computer Science 2025-11-20 Marcus Schaefer , Daniel Štefankovič

We study the Hadamard product of two varieties $V$ and $W$, with particular attention to the situation when one or both of $V$ and $W$ is a binomial variety. The main result of this paper shows that when $V$ and $W$ are both binomial…

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…

Combinatorics · Mathematics 2019-07-16 Ka Hin Leung , Koji Momihara

Consider l lines in P^2 such that no three lines meet in a point. Let X(l) denote all points of intersections of these l lines. We describe all pairs (d,l) such that generic degree d curve in P^2 contains a X(l).

Algebraic Geometry · Mathematics 2010-01-26 Enrico Carlini , Adam Van Tuyl