Results 71 to 80 of about 3,056 (285)
International Journal for Numerical Methods in Fluids, EarlyView.This article provides important geometric formulas for node‐centered, edge‐based schemes in any number of dimensions. These formulas are noteworthy, as they do not require the explicit formation of dual regions. We prove several key geometric results, with a particular focus on the four‐dimensional case, due to potential space‐time applications ...
Nicholas Tufillaro +2 more
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Sigma-maps on triangular algebras [PDF]
, 2018 Triangular algebras were introduced by Chase in the early 1960s. He ended up with these structures in the course of his study of the asymmetric behavior of semi-hereditary rings.
Sánchez-Ortega, Juana +3 more
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Differential polynomial identities of upper triangular matrices of size three [PDF]
, 2023 We determine the differential polynomial identities of $3\times 3$ upper triangular matrices over a base field of characteristic zero, under the action of its full Lie algebra of derivations.
Nardozza V.
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Algebraic and Triangular n-Hyponormal Operators [PDF]
Proceedings of the American Mathematical Society, 1995 In this paper we shall prove that if an operator T ∈
openaire +1 more source
Journal of Applied Econometrics, EarlyView.ABSTRACT We present four novel tests of equal predictive accuracy and encompassing á Pitarakis (2023, 2025) for factor‐augmented regressions. Factors are estimated using cross‐section averages (CAs) of grouped series and our theoretical findings are empirically relevant: asymptotic normality, robustness to an overspecification of the number of factors,
Alessandro Morico, Ovidijus Stauskas
wiley +1 more source
Jordan maps on triangular algebras
Linear Algebra and its Applications, 2007 For \(x,y\in R\), an associative ring, let \(x\circ y=xy+yx\). Given rings \(R\) and \(S\), maps \(f\colon R\to S\) and \(g\colon S\to R\) form a Jordan pair if for all \(x\in R\) and \(y\in S\), \(f(x\circ g(y))=f(x)\circ y\) and \(g(y\circ f(x))=g(y)\circ x\).
openaire +2 more sources
Stable Cuts, NAC‐Colourings and Flexible Realisations of Graphs
Journal of Graph Theory, EarlyView.ABSTRACT A (2‐dimensional) realisation of a graph G $G$ is a pair ( G , p ) $(G,p)$, where p $p$ maps the vertices of G $G$ to R 2 ${{\mathbb{R}}}^{2}$. A realisation is flexible if it can be continuously deformed while keeping the edge lengths fixed, and rigid otherwise.
Katie Clinch +5 more
wiley +1 more source
Graded identities of block-triangular matrices [PDF]
, 2016 Let F be an infinite field and UT(d(1),..., d(n)) be the algebra of upper block-triangular matrices over F. In this paper we describe a basis for the C-graded polynomial identities of UT(d(1),..., d(n)), with an elementary grading induced by an n-tuple ...
Pereira da Silva e Silva, Diogo Diniz +1 more
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Generating Helical Polymorphic Beams Using Dielectric Metasurfaces
Laser &Photonics Reviews, EarlyView.Helix‐shaped polymorphic beams are optical fields whose intensity maxima spiral around the propagation axis, enabling particle manipulation through attractive or repulsive forces. Traditionally requiring expensive spatial light modulators, metasurfaces now provide a compact, cost‐effective alternative. This work demonstrates general helical polymorphic
Maryam Setareh +3 more
wiley +1 more source
Jordan {g,h}-derivations on triangular algebras
Open Mathematics, 2020 In this article, we give a sufficient and necessary condition for every Jordan {g,h}-derivation to be a {g,h}-derivation on triangular algebras. As an application, we prove that every Jordan {g,h}-derivation on τ(N)\tau ({\mathscr{N}}) is a {g,h ...
Kong Liang, Zhang Jianhua
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