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Related papers: Off-diagonally symmetric alternating sign matrices

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We study a further refinement of the standard refined enumeration of alternating sign matrices (ASMs) according to their first two rows instead of just the first row, and more general "d-refined" enumerations of ASMs according to the first…

Combinatorics · Mathematics 2009-04-15 Ilse Fischer , Dan Romik

We give two algorithms for output-sparse matrix multiplication (OSMM), the problem of multiplying two $n \times n$ matrices $A, B$ when their product $AB$ is promised to have at most $O(n^{\delta})$ many non-zero entries for a given value…

Data Structures and Algorithms · Computer Science 2025-08-15 Huck Bennett , Karthik Gajulapalli , Alexander Golovnev , Evelyn Warton

In 2007, the first author gave an alternative proof of the refined alternating sign matrix theorem by introducing a linear equation system that determines the refined ASM numbers uniquely. Computer experiments suggest that the numbers…

Combinatorics · Mathematics 2014-03-04 Ilse Fischer , Lukas Riegler

In a previous paper, one of us pointed out that the anomalous dimension matrices for all physical processes that have been calculated to date are complex symmetric, if stated in an orthonormal basis. In this paper we prove this fact and…

High Energy Physics - Phenomenology · Physics 2009-01-27 Michael H. Seymour , Malin Sjodahl

We study anomalies in time-reversal ($\mathbb{Z}_2^T$) and $U(1)$ symmetric topological orders. In this context, an anomalous topological order is one that cannot be realized in a strictly $(2+1)$-D system but can be realized on the surface…

Strongly Correlated Electrons · Physics 2024-06-21 Matthew F. Lapa , Michael Levin

First we give an overview of the known supplementary difference sets (SDS) (A_i), i=1..4, with parameters (n;k_i;d), where k_i=|A_i| and each A_i is either symmetric or skew and k_1 + ... + k_4 = n + d. Five new Williamson matrices over the…

Combinatorics · Mathematics 2010-02-14 Dragomir Z. Djokovic

Graph labeling is a well-known and intensively investigated problem in graph theory. Sparse anti-magic squares are useful in constructing vertex-magic labeling for graphs. For positive integers $n,d$ and $d<n$, an $n\times n$ array $A$…

Combinatorics · Mathematics 2020-02-20 Guangzhou Chen , Wen Li , Ming Zhong , Bangying Xin

An oblivious subspace embedding (OSE), characterized by parameters $m,n,d,\epsilon,\delta$, is a random matrix $\Pi\in \mathbb{R}^{m\times n}$ such that for any $d$-dimensional subspace $T\subseteq \mathbb{R}^n$, $\Pr_\Pi[\forall x\in T,…

Data Structures and Algorithms · Computer Science 2023-07-14 Yi Li , Mingmou Liu

Any finite-dimensional commutative (associative) graded algebra with all nonzero homogeneous subspaces one-dimensional is defined by a symmetric coefficient matrix. This algebraic structure gives a basic kind of $A$-graded algebras…

Rings and Algebras · Mathematics 2026-03-23 Yunnan Li , Shi Yu

We construct a number of new (v;r,s;lambda) supplementary difference sets (SDS) with v odd and lambda = (r+s)-(v-1)/2. In particular, these give rise to D-optimal matrices of the four new orders 206, 242, 262, 482 constructed here for the…

Combinatorics · Mathematics 2013-01-22 Dragomir Z. Djokovic , Ilias S. Kotsireas

Let $D$ be an oriented link diagram with the set of regions $\operatorname{r}_{D}$. We define a symmetric map (or matrix) $\operatorname{\tau}_{D}\colon\operatorname{r}_{D}\times \operatorname{r}_{D} \to \mathbb{Z}[x]$ that gives rise to an…

Geometric Topology · Mathematics 2018-01-19 Rinat Kashaev

An "oblivious subspace embedding (OSE)" given some parameters eps,d is a distribution D over matrices B in R^{m x n} such that for any linear subspace W in R^n with dim(W) = d it holds that Pr_{B ~ D}(forall x in W ||B x||_2 in (1 +/-…

Data Structures and Algorithms · Computer Science 2012-11-07 Jelani Nelson , Huy L. Nguyen

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

Alternating sign matrices (ASMs) arise as the Dedekind-MacNeille completion of the Bruhat order on the symmetric group. They enjoy fruitful combinatorial and geometric properties, with a particularly rich history on enumerations and…

Combinatorics · Mathematics 2026-04-30 Yibo Gao , Hanlin Xu

A matrix is incomplete when some of its entries are missing. A Robinson incomplete symmetric matrix is an incomplete symmetric matrix whose non-missing entries do not decrease along rows and columns when moving toward the diagonal. A…

Discrete Mathematics · Computer Science 2021-01-11 Julio Aracena , Christopher Thraves Caro

It is known that any symmetric matrix $M$ with entries in $\R[x]$ and which is positive semi-definite for any substitution of $x\in\R$, has a Smith normal form whose diagonal coefficients are constant sign polynomials in $\R[x]$. We…

Rings and Algebras · Mathematics 2009-09-09 Ronan Quarez

In this paper, we answer the various forms of nonnegative inverse eigenvalue problems with prescribed diagonal entries for order three: real or complex general matrices, symmetric stochastic matrices, and real or complex doubly stochastic…

Spectral Theory · Mathematics 2018-06-22 Jin Ok Hwang , Donggyun Kim

In many problems in Computational Physics and Chemistry, one finds a special kind of sparse matrices, termed "banded matrices". These matrices, which are defined as having non-zero entries only within a given distance from the main…

Computational Physics · Physics 2013-06-21 Pablo García-Risueño , Pablo Echenique

A multidimensional nonnegative matrix is called polystochastic if the sum of its entries over each line is equal to $1$. The permanent of a multidimensional matrix is the sum of products of entries over all diagonals. We prove that if $d$…

Combinatorics · Mathematics 2025-12-01 A. L. Perezhogin , V. N. Potapov , A. A. Taranenko , S. Yu. Vladimirov

The nineteen-vertex model on a periodic lattice with an anti-diagonal twist is investigated. Its inhomogeneous transfer matrix is shown to have a simple eigenvalue, with the corresponding eigenstate displaying intriguing combinatorial…

Mathematical Physics · Physics 2016-06-22 Christian Hagendorf , Alexi Morin-Duchesne