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We consider orthogonal transformations of arbitrary square matrices to a form where all diagonal entries are equal. In our main results we treat the simultaneous transformation of two matrices and the symplectic orthogonal transformation of…

Numerical Analysis · Mathematics 2020-01-29 Tobias Damm , Heike Fassbender

The aim of this note is to discuss resolution theorems that are useful in the study of semi log canonical varieties.

Algebraic Geometry · Mathematics 2008-12-19 János Kollár

We investigate invertible matrices over finite additively idempotent semirings. The main result provides a criterion for the invertibility of such matrices. We also give a construction of the inverse matrix and a formula for the number of…

Rings and Algebras · Mathematics 2012-08-13 Andreas Kendziorra , Stefan E. Schmidt , Jens Zumbrägel

We consider $m \times s$ matrices (with $m\geq s$) in a real affine subspace of dimension $n$. The problem of finding elements of low rank in such spaces finds many applications in information and systems theory, where low rank is…

Symbolic Computation · Computer Science 2019-07-19 Didier Henrion , Simone Naldi , Mohab Safey El Din

The least square solution of minimum norm of a rectangular linear system of equations can be found out iteratively by using matrix splittings. However, the convergence of such an iteration scheme arising out of a matrix splitting is…

Numerical Analysis · Mathematics 2025-08-07 Chinmay Kumar Giri , Debasisha Mishra

We consider real non-symmetric matrices and their factorisation as a product of real symmetric matrices. The number of complex eigenvalues of the original matrix reveals restrictions on such factorisations as we shall prove.

Numerical Analysis · Mathematics 2025-03-25 Andy Wathen

Finite linear least squares is one of the core problems of numerical linear algebra, with countless applications across science and engineering. Consequently, there is a rich and ongoing literature on algorithms for solving linear least…

Numerical Analysis · Mathematics 2021-10-27 Paz Fink Shustin , Haim Avron

Arithmetical structures on graphs were first introduced in \cite{Lorenzini89}. Later in \cite{arithmetical} they were further studied in the setting of square non-negative integer matrices. In both cases, necessary and sufficient conditions…

Number Theory · Mathematics 2022-02-17 Carlos E. Valencia , R. R. Villagrán

This short course offers a new perspective on randomized algorithms for matrix computations. It explores the distinct ways in which probability can be used to design algorithms for numerical linear algebra. Each design template is…

Numerical Analysis · Mathematics 2025-09-23 Anastasia Kireeva , Joel A. Tropp

Motivated by a certain molecular reconstruction methodology in cryo-electron microscopy, we consider the problem of solving a linear system with two unknown orthogonal matrices, which is a generalization of the well-known orthogonal…

Optimization and Control · Mathematics 2017-03-07 Teng Zhang , Amit Singer

We give an algorithm for constructing the algebraic hull of a given matrix Lie algebra in characteristic zero. It is based on an algorithm for finding integral linear dependencies of the roots of a polynomial, that is probably of…

Rings and Algebras · Mathematics 2007-05-23 Claus Fieker , Willem de Graaf

We study certain linear algebra algorithms for recursive block matrices. This representation has useful practical and theoretical properties. We summarize some previous results for block matrix inversion and present some results on…

Symbolic Computation · Computer Science 2024-07-08 Stephen M. Watt

Using semi-tensor product of matrices, the structures of several kinds of symmetric games are investigated via the linear representation of symmetric group in the structure vector of games as its representation space. First of all, the…

Computer Science and Game Theory · Computer Science 2017-03-09 Daizhan Cheng , Ting Liu

The main question we raise here is the following one: given a real orthogonal n by n matrix X, is it true that there exists a rational orthogonal matrix Y having the same zero-pattern? We conjecture that this is the case and prove it for…

Combinatorics · Mathematics 2011-12-30 Dragomir Z. Djokovic , Simone Severini , Ferenc Szollosi

We obtain minimal dimension matrix representations for each indecomposable five-dimensional Lie algebra over $\R$ and justify in each case that they are minimal. In each case a matrix Lie group is given whose matrix Lie algebra provides the…

Differential Geometry · Mathematics 2014-02-21 Ryad Ghanam , G. Thompson

In this paper we consider disjoint decomposition of algebraic and non-linear partial differential systems of equations and inequations into so-called simple subsystems. We exploit Thomas decomposition ideas and develop them into a new…

Commutative Algebra · Mathematics 2015-05-19 Thomas Bächler , Vladimir Gerdt , Markus Lange-Hegermann , Daniel Robertz

We obtain a necessary and sufficient condition for the existence of equivariant real structures on complex symmetric spaces for semisimple groups and discuss how to determine the number of equivalence classes for such structures.

Algebraic Geometry · Mathematics 2021-05-25 Lucy Moser-Jauslin , Ronan Terpereau

The article presents a matrix differential operator and a pseudoinverse matrix differential operator for finding a particular solution to nonhomogeneous linear ordinary differential equations (ODE) with constant coefficients with special…

General Mathematics · Mathematics 2021-01-07 Jozef Fecenko

Properties of partial integrals such as real and complex-valued polynomial, multiple polynomial, exponential, and conditional for ordinary differential systems are studied. The possibilities of constructing first integrals and last…

Classical Analysis and ODEs · Mathematics 2018-09-20 V. N. Gorbuzov

We define the field $\mathbb{L}$ of logarithmic hyperseries, construct on $\mathbb{L}$ natural operations of differentiation, integration, and composition, establish the basic properties of these operations, and characterize these…

Logic · Mathematics 2018-10-04 Lou van den Dries , Joris van der Hoeven , Elliot Kaplan