Results 21 to 30 of about 12,423 (291)
Dual active-set algorithm for optimal 3-monotone regression [PDF]
Известия Саратовского университета. Новая серия: Математика. Механика. Информатика, 2022 The paper considers a shape-constrained optimization problem of constructing monotone regression which has gained much attention over the recent years. This paper presents the results of constructing the nonlinear regression with $3$-monotone constraints.
Gudkov, Alexandr A. +2 more
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Demonstratio Mathematica, 2023 The classification of the phase portraits is one of the classical and difficult problems in the qualitative theory of polynomial differential systems in R2{{\mathbb{R}}}^{2}, particularly for quadratic systems.
Benterki Rebiha, Belfar Ahlam
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Covariants, Invariant Subsets, and First Integrals [PDF]
Épijournal de Géométrie Algébrique, 2020 Let $k$ be an algebraically closed field of characteristic 0, and let $V$ be a finite-dimensional vector space. Let $End(V)$ be the semigroup of all polynomial endomorphisms of $V$.
Frank Grosshans, Hanspeter Kraft
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Twin Polynomial Vector Fields of Arbitrary Degree
Bulletin of the Brazilian Mathematical Society, New Series, 2021 In this paper we study polynomial vector fields on C2 of degree larger than 2 with n2 isolated singularities. More precisely, we show that if two polynomial vector fields share n2-1 singularities with the same spectra (trace and determinant) and from these singularities n2-2 have the same positions, then both vector fields have identical position and ...
Llibre, Jaume, Valls, Clàudia
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Equivariant decomposition of polynomial vector fields [PDF]
Communications in Contemporary Mathematics, 2020 To compute the unique formal normal form of families of vector fields with nilpotent linear part, we choose a basis of the Lie algebra consisting of orbits under the action of the nilpotent linear part. This creates a new problem: to find explicit formulas for the structure constants in this new basis. These are well known in the 2D case, and recently
Mokhtari, Fahimeh, Sanders, J.A.
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Explicit Geometric Integration of Polynomial Vector Fields [PDF]
BIT Numerical Mathematics, 2004 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Mclachlan, Robert Iain. +1 more
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On Polynomial Hamiltonian Planar Vector Fields
Journal of Differential Equations, 1993 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Cima, A., Gasull, A., Manosas, F.
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Cofactors and equilibria for polynomial vector fields [PDF]
Proceedings of the Royal Society of Edinburgh: Section A Mathematics, 2021 We present a relationship between the existence of equilibrium points of differential systems and the cofactors of the invariant algebraic curves and the exponential factors of the system.
Ferragut, Antoni, Llibre, Jaume
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The global dynamics of a class of nonlinear vector fields in $\mathbb{R}^3$
Electronic Journal of Qualitative Theory of Differential Equations, 2014 In this paper, we study the geometric properties of a class of nonlinear polynomial vector fields in $\mathbb{R}^3$. By virtue of their induced vector fields, their global topological structures are discussed and we get that there are at least 82 types
Jinhui Zhang +2 more
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On the polynomial vector fields on [PDF]
Proceedings of the Royal Society of Edinburgh: Section A Mathematics, 2011 Let X be a polynomial vector field of degree n on M, M = ℝm. The dynamics and the algebraic-geometric properties of the vector fields X have been studied intensively, mainly for the case when M = ℝm, and especially when n = 2. Several papers have been dedicated to the study of the homogeneous polynomial vector field of degree n on $\mathbb{S}^2 ...
Jaume Llibre, Yulin Zhao
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