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Related papers: Bordering for spectrally arbitrary sign patterns

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A sign pattern is a matrix whose entries belong to the set $\{+,-,0\}$. A sign pattern requires a unique inertia if every real matrix in its qualitative class has the same inertia. Symmetric tree sign patterns requiring a unique inertia has…

Combinatorics · Mathematics 2025-09-01 Partha Rana , Sriparna Bandopadhyay

We extend the ultraspherical spectral method to solving nonlinear ODE boundary value problems. We propose to use the inexact Newton-GMRES framework for which an effective preconditioner can be constructed and a fast Jacobian-vector…

Numerical Analysis · Mathematics 2023-07-03 Ouyuan Qin , Kuan Xu

In this work, we define a modification of a bordered construction for self-dual codes which utilises $\lambda$-circulant matrices. We provide the necessary conditions for the construction to produce self-dual codes over finite commutative…

Information Theory · Computer Science 2023-01-18 Joe Gildea , Adrian Korban , Adam Michael Roberts , Alexander Tylyshchak

The usefulness of recursive equations to compute scattering matrix elements for arbitrary processes is discussed. Explicit results at tree and one-loop order, obtained by the HELAC/PHEGAS package that is based on the Dyson-Schwinger…

High Energy Physics - Phenomenology · Physics 2009-11-11 P. Draggiotis , A. van Hameren , R. Kleiss , A. Lazopoulos , C. G. Papadopoulos , M. Worek

Alternating direction multiplication is a powerful technique for solving convex optimisation problems. When challenging subproblems are encountered in the real world, it is useful to solve them by introducing neighbourhood terms. When the…

Optimization and Control · Mathematics 2024-04-29 Boran Wang

We consider open XXX spins chain with two general boundary matrices submitted to one constraint, which is equivalent to the possibility to put the two matrices in a triangular form. We construct Bethe vectors from a generalized algebraic…

Mathematical Physics · Physics 2015-06-11 S. Belliard , N. Crampe , E. Ragoucy

We present a triangulation--independent area--ordering prescription which naturally generalizes the well known path ordering one. For such a prescription it is natural that the two--form ``connection'' should carry three ``color'' indices…

High Energy Physics - Theory · Physics 2009-11-11 E. T. Akhmedov

Boundary samples are special inputs to artificial neural networks crafted to identify the execution environment used for inference by the resulting output label. The paper presents and evaluates algorithms to generate transparent boundary…

Machine Learning · Computer Science 2021-06-15 Alexander Schlögl , Tobias Kupek , Rainer Böhme

We give an efficient algorithm which can obtain a relative error approximation to the spectral norm of a matrix, combining the power iteration method with some techniques from matrix reconstruction which use random sampling.

Data Structures and Algorithms · Computer Science 2011-04-13 Malik Magdon-Ismail

We recall the concept of Baxterisation of an R-matrix, or of a monodromy matrix, which corresponds to build, from one point in the $ R$-matrix parameter space, the algebraic variety where the spectral parameter(s) live. We show that the…

High Energy Physics - Theory · Physics 2015-06-25 S. Boukraa , J-M. Maillard

We theoretically introduce several types of arbitrary polarization retarders constructed from sequences of half-wave and quarter-wave plates, each rotated at specific angles. By integrating these arbitrary polarization retarders with…

Optics · Physics 2025-04-09 Hayk L. Gevorgyan , Andon A. Rangelov

We determine the structure of linear maps on complex (real) square matrices sending unitary (orthogonal) matrices to multiples of unitary (orthogonal) matrices. The result is used to determine the linear preservers of matrix pairs…

Functional Analysis · Mathematics 2025-10-08 Bojan Kuzma , Chi-Kwong Li , Edward Poon

We construct and justify leading order weakly nonlinear geometric optics expansions for nonlinear hyperbolic initial value problems, including the compressible Euler equations. The technique of simultaneous Picard iteration is employed to…

Analysis of PDEs · Mathematics 2012-07-18 Matthew Hernandez

We give some new methods for perfect reconstruction from frame and sampling erasures in finitely many steps. By bridging an erasure set we mean replacing the erased Fourier coefficients of a function with respect to a frame by appropriate…

Functional Analysis · Mathematics 2014-09-19 David R. Larson , Sam L. Scholze

We propose a spectral clustering algorithm for analyzing the dependence structure of multivariate extremes. More specifically, we focus on the asymptotic dependence of multivariate extremes characterized by the angular or spectral measure…

Machine Learning · Statistics 2023-08-02 Marco Avella Medina , Richard A. Davis , Gennady Samorodnitsky

A random medium can serve as a controllable arbitrary spectral filter with spectral resolution determined by the inverse of the interaction time of the light in the medium. We use wavefront shaping to implement an arbitrary spectral…

Optics · Physics 2015-06-05 Eran Small , Ori Katz , Yefeng Guan , Yaron Silberberg

We report an optical method of generating arbitrary polarization states by manipulating the thicknesses of a pair of uniaxial birefringent plates, the optical axes of which are set at a crossing angle of {\pi}/4. The method has the…

Optics · Physics 2023-08-03 Akihiro Tomura , Makoto Nomura , Chiaki Ohae , Masayuki Katsuragawa

In this paper we develop and apply methods for the spectral analysis of non-self-adjoint tridiagonal infinite and finite random matrices, and for the spectral analysis of analogous deterministic matrices which are pseudo-ergodic in the…

Spectral Theory · Mathematics 2013-05-14 Simon N. Chandler-Wilde , Ratchanikorn Chonchaiya , Marko Lindner

The paper presents an analysis of the possible spectra manipulation and its consequence for the specific application of XCT. The focus was on the modification of the registered spectra dominantly by the sewing/stitching method. A model…

Atomic Physics · Physics 2024-06-04 A. J. Arikkat , K. A. Janulewicz , C. M. Kim , P. Wachulak

In this survey we describe a recently-developed technique for bounding the number (and controlling the typical structure) of finite objects with forbidden substructures. This technique exploits a subtle clustering phenomenon exhibited by…

Combinatorics · Mathematics 2018-01-16 József Balogh , Robert Morris , Wojciech Samotij