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Related papers: Bounded ratios for Lorentzian matrices

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We establish improved convergence rates for curved boundary element methods applied to the three-dimensional (3D) Laplace and Helmholtz equations with smooth geometry and data. Our analysis relies on a precise analysis of the consistency…

Numerical Analysis · Mathematics 2025-07-21 Luiz Maltez Faria , Pierre Marchand , Hadrien Montanelli

For a given complex square matrix $A$ with constant row sum, we establish two new eigenvalue inclusion sets. Using these bounds, first we derive bounds for the second largest and smallest eigenvalues of adjacency matrices of $k$-regular…

Combinatorics · Mathematics 2020-08-27 Ranjit Mehatari , M. Rajesh Kannan

The b-boundary is a mathematical tool used to attach a topological boundary to incomplete Lorentzian manifolds using a Riemaniann metric called the Schmidt metric on the frame bundle. In this paper, we give the general form of the Schmidt…

General Relativity and Quantum Cosmology · Physics 2018-04-03 Yafet Sanchez Sanchez , Cesar Merlin , Ricardo Reynoso Fuentes

The boundary problem is considered for inhomogeneous increasing random walks on the square lattice ${\mathbb Z}_+^2$ with weighted edges. Explicit solutions are given for some instances related to the classical and generalized number…

Probability · Mathematics 2009-09-29 Alexander Gnedin

We study the spectral norm of large rectangular random Toeplitz and circulant matrices with independent entries. For Toeplitz matrices, we show that the scaled norm converges to the norm of a bilinear operator defined via the pointwise…

Probability · Mathematics 2025-09-05 Alexei Onatski

Consider the deformation of the standard Lorentzian metric on the anti de-Sitter space along the fibers of the Hopf fibration. We study the universal covering of this Lorentzian manifold to exclude a priori presence of time-like cycles. We…

Differential Geometry · Mathematics 2025-05-07 A. V. Podobryaev

We formulate and discuss the affine-invariant matrix midrange problem on the cone of $n\times n$ positive definite Hermitian matrices $\mathbb{P}(n)$, which is based on the Thompson metric. A particular computationally efficient midpoint of…

Optimization and Control · Mathematics 2022-06-29 Cyrus Mostajeran , Christian Grussler , Rodolphe Sepulchre

Irregular boundary lines can be characterized by fractal dimension, which provides important information for spatial analysis of complex geographical phenomena such as cities. However, it is difficult to calculate fractal dimension of…

Physics and Society · Physics 2023-08-09 Yanguang Chen

In this paper we consider faultfree tromino tilings of rectangles and characterize rectangles that admit such tilings. We introduce the notion of {\it crossing numbers} for tilings and derive bounds on the crossing numbers of faultfree…

Combinatorics · Mathematics 2007-05-23 Mridul Aanjaneya , Sudebkumar Prasant Pal

In a given hypercube, draw grid lines parallel to the edges, and consider all hypercuboids (or hypercubes) whose edges are lying on the grid lines or the boundary. We find the limit of the value of the ratio of the arithmetic mean of the…

Combinatorics · Mathematics 2025-01-03 Takashi Hirotsu

We prove existence and regularity of minimizers for a class of functionals defined on Borel sets in $R^n$. Combining these results with a refinement of the selection principle introduced by the authors in arXiv:0911.0786, we describe a…

Analysis of PDEs · Mathematics 2011-01-04 Marco Cicalese , Gian Paolo Leonardi

We establish basic information about border rank algorithms for the matrix multiplication tensor and other tensors with symmetry. We prove that border rank algorithms for tensors with symmetry (such as matrix multiplication and the…

Algebraic Geometry · Mathematics 2016-02-01 J. M. Landsberg , Mateusz Michałek

The main aim of this work is to apply the study of the asymptotic behaviour of generalized eigenvalues between infinite Hermitian definite positive matrices in an important question regarding the location of zeros of Sobolev orthogonal…

Functional Analysis · Mathematics 2023-05-26 C. Escribano , R. Gonzalo

Given a real matrix A with n columns, the problem is to approximate the Gram product AA^T by c << n weighted outer products of columns of A. Necessary and sufficient conditions for the exact computation of AA^T (in exact arithmetic) from c…

Numerical Analysis · Mathematics 2014-05-16 John T. Holodnak , Ilse C. F. Ipsen

Spatial random permutations were originally studied due to their connections to Bose-Einstein condensation, but they possess many interesting properties of their own. For random permutations of a regular lattice with periodic boundary…

Probability · Mathematics 2015-06-17 Volker Betz

Motivated by applications to perverse sheaves, we study combinatorics of two cell decompositions of the symmetric product of the complex line, refining the complex stratification by multiplicities. Contingency matrices, appearing in…

Geometric Topology · Mathematics 2020-07-08 Mikhail Kapranov , Vadim Schechtman

We determine, for all three-dimensional non-unimodular Lie groups equipped with a Lorentzian metric, the set of homogeneous geodesics through a point. Together with the results of [C] and [CM2], this leads to the full classification of…

Differential Geometry · Mathematics 2008-01-09 Giovanni Calvaruso , Rosa Anna Marinosci

For a manifold with nonpositive curvature, the Martin boundary is described by the behavior of normalized Green's functions at infinity. A classical result by Anderson and Schoen states that if the manifold has pinched negative curvature,…

Differential Geometry · Mathematics 2017-11-21 Ran Ji

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

Consider an arrangement of $k$ lines intersecting the unit square. There is some minimum scaling factor so that any placement of a rectangle with aspect ratio $1 \times p$ with $p\geq 1$ must non-transversely intersect some portion of the…

Computational Geometry · Computer Science 2022-01-05 Bradley McCoy , Eli Quist , Anna Schenfisch