Results 111 to 120 of about 5,897 (225)
Condicionamiento y alta precisión en problemas espectrales estructurados [PDF]
, 2007 Esta memoria trata dos aspectos relacionados con la precisión de algoritmos espectrales para problemas matriciales estructurados: 1) Se definen números de condición estructurados de autovalores múltiples, eventualmente defectivos, y se obtienen fórmulas ...
Peláez Montalvo, María José
core
Modified Lagrange–Jacobi Functions
MathematicsThis paper presents modified Lagrange–Jacobi functions derived from the sine, exponential, and hyperbolic tangent coordinate transformations. The resulting Lagrange–Jacobi functions and their respective matrix elements for observables can be reduced to ...
Gaotsiwe Joel Rampho
doaj +1 more source
A class of matrix-valued polynomials generalizing Jacobi polynomials
Journal of Approximation Theory, 2009 A hierarchy of matrix-valued polynomials which generalize the Jacobi polynomials is found. Defined by a Rodrigues formula, they are also products of a sequence of differential operators. Each class of polynomials is complete, satisfies a two-step recurrence relation, integral inter-relations, and quasi-orthogonality relations.
openaire +3 more sources
Properties of the scattering matrix and dispersion estimates for Jacobi operators
Journal of Mathematical Analysis and Applications, 2016 10 ...
Iryna Egorova +2 more
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Four‐Dimensional pp‐Wave Lie Groups and Harmonic Curvature
Mathematische Nachrichten, Volume 299, Issue 7, Page 1751-1780, July 2026.ABSTRACT We determine all four‐dimensional Lie groups which have harmonic curvature. In parallel, a description of four‐dimensional pp‐wave Lie groups is obtained.
E. García‐Río +2 more
wiley +1 more source
Journal of Advances in Modeling Earth Systems, Volume 18, Issue 7, July 2026.Abstract Two of the challenges for paleoclimate data assimilation (PDA) are the extreme sparsity of proxy observations and the non‐Gaussian nature of background errors in the climate system. In this study, we develop a latent‐space variational data assimilation framework based on variational autoencoders (VAEs) and latent‐space minimization (VAE‐Var ...
Zikuan Lin +8 more
wiley +1 more source
On the construction of a Jacobi matrix from mixed given data [PDF]
, 1979 It is shown that a n×n Jacobi matrix is uniquely determined by its n eigenvalues and by the selected set of n − 1 entries in the ...
Harry Hochstadt, Hochstadt, Harry
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Diversity and Distributions, Volume 32, Issue 7, July 2026.ABSTRACT Aim Our research aimed to assess the beta diversity of Chironomidae (Diptera) and faunal connections across springs, streams, and rivers within the Skadar Lake basin, a Mediterranean biodiversity hotspot, using DNA barcoding. Location Skadar Lake basin—a Mediterranean biodiversity hotspot. Methods We analysed mitochondrial cytochrome c oxidase
Piotr Gadawski +8 more
wiley +1 more source
A first-order spectral phase transition in a class of periodically modulated Hermitian Jacobi matrices [PDF]
Opuscula Mathematica, 2008 We consider self-adjoint unbounded Jacobi matrices with diagonal \(q_n = b_{n}n\) and off-diagonal entries \(\lambda_n = n\), where \(b_{n}\) is a \(2\)-periodical sequence of real numbers. The parameter space is decomposed into several separate regions,
Irina Pchelintseva
doaj
A relative Poincaré–Birkhoff theorem
Bulletin of the London Mathematical Society, Volume 58, Issue 7, July 2026.Abstract A. Moreno and Otto van Koert proved a generalised version of the classical Poincaré–Birkhoff theorem, for Liouville domains of any dimension. In this article, we prove a relative version for Lagrangians with Legendrian boundary. This gives interior chords of arbitrary large length, provided that the twist condition introduced by Moreno and van
Agustin Moreno, Arthur Limoge
wiley +1 more source