Results 31 to 40 of about 81,984 (133)

Phase portraits of quadratic polynomial differential systems having as solution some classical planar algebraic curves of degree 4

Electronic Journal of Differential Equations, 2019
We classify the phase portraits of quadratic polynomial differential systems having some relevant classic quartic algebraic curves as invariant algebraic curves, i.e. these curves are formed by orbits of the quadratic polynomial differential system.
Rebiha Benterki, Jaume Llibre
doaj  

Desarrollo de funciones de índice de sitio para Eucalyptus grandis cultivado en la Mesopotamia argentina [PDF]

RIA: Revista Investigaciones Agropecuarias, 2011
ResumenSe desarrollaron modelos para la estimación del índice de sitio para Eucalyptus grandis implantado en la Mesopotamia argentina. Dicha estimación se llevó a cabo a través de la evaluación de una base general de datos que contó con 106 parcelas (439
CRECHI, E.H, FASSOLA, H.E., KELLER, A.E, BARTH, S.R   +3 more
doaj  

The irreducible components of the moduli space of dihedral covers of algebraic curves [PDF]

, 2012
In this paper we introduce a new invariant for the action of a finite group $G$ on a compact complex curve of genus $g$. With the aid of this invariant we achieve the classification of the components of the moduli space of curves with an effective action
F. Catanese, Michael Loenne, Fabio Perroni   +2 more
semanticscholar   +1 more source

Invariant varieties for polynomial dynamical systems [PDF]

, 2009
We study algebraic dynamical systems (and, more generally, $\sigma$-varieties) $\Phi:{\mathbb A}^n_{\mathbb C} \to {\mathbb A}^n_{\mathbb C}$ given by coordinatewise univariate polynomials by refining a theorem of Ritt.
Alice Medvedev, T. Scanlon
semanticscholar   +1 more source

Cubic and quartic planar differential systems with exact algebraic limit cycles

Electronic Journal of Differential Equations, 2011
We construct cubic and quartic polynomial planar differential systems with exact limit cycles that are ovals of algebraic real curves of degree four. The result obtained for the cubic case generalizes a proposition of [9].
Ahmed Bendjeddou, Rachid Cheurfa
doaj  

Center conditions for a cubic differential system with one invariant straight line and one invariant conic

Acta et Commentationes: Ştiinţe Exacte şi ale Naturii
In this work we find the center conditions for a cubic system of differential equations with a critical point of a center or a focus type having one invariant straight line and one invariant conic. The center-focus problem is studied by using the Darboux
Dumitru Cozma
doaj   +1 more source

Qualitative analysis of polynomial differential systems with the line at infinity of maximal multiplicity: exploring linear, quadratic, cubic, quartic, and quintic cases

Acta et Commentationes: Ştiinţe Exacte şi ale Naturii
This article investigates the phase portraits of polynomial differential systems with maximal multiplicity at the line at infinity. The study explores theoretical foundations, including algebraic multiplicity definitions, to establish the groundwork for
Vadim Repeșco
doaj   +1 more source

Coexistence of algebraic and non-algebraic limit cycles for quintic polynomial differential systems

Electronic Journal of Differential Equations, 2017
In the work by Gine and Grau [11], a planar differential system of degree nine admitting a nested configuration formed by an algebraic and a non-algebraic limit cycles explicitly given was presented.
Ahmed Bendjeddou, Rachid Cheurfa
doaj  

Quadratic systems with an invariant algebraic curve of degree 3 and a Darboux invariant

Electronic Journal of Differential Equations, 2021
Jaume Llibre, Regilene D. S. Oliveira, Camila A. B. Rodrigues   +2 more
doaj  

Holomorphic foliations in ${\Bbb C}{\Bbb P}(2)$ having an invariant algebraic curve

, 1991
D. Cerveau, A. L. Neto
semanticscholar   +1 more source