Browsing Articles publicats (Matemàtica) by Title
Now showing items 143-162 of 274
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Integrability conditions of a resonant saddle in generalized Liénard-like complex polynomial differential systems
(Elsevier, 2017)We consider a complex differential system with a resonant saddle at the origin. We compute the resonant saddle quantities and using Gröbner bases we find the integrability conditions for such systems up to a certain degree. ... -
Integrability conditions of a resonant saddle in Liénard-like complex systems
(Elsevier, 2016)We consider a complex differential system with a resonant saddle that remind the classical Liénard systems in the real plane. For such systems we determine the conditions of analytic integrability of the resonant saddle. -
Integrability conditions of a resonant saddle perturbed with homogeneous quintic nonlinearities
(Springer, 2015)In this work we complete the integrability conditions (i.e. conditions for the existence of a local analytic first integral) for a family of a resonant saddle perturbed with homogeneous quintic nonlinearities studied in a ... -
Integrability of a linear center perturbed by a fifth degree homogeneous polynomial
(Universitat Autònoma de Barcelona. Departament de Matemàtiques, 1997)In this work we study the integrability of two-dimensional autonomous system in the plane with linear part of center type and non-linear part given by homogeneous polynomials of fifth degree. We give a simple characterisation ... -
Integrability of a linear center perturbed by a fourth degree homogeneous polynomial
(Universitat Autònoma de Barcelona. Departament de Matemàtiques, 1996)In this work we study the integrability of a two-dimensional autonomous system in the plane with linear part of center type and non-linear part given by homogeneous polynomials of fourth degree. We give sufficient conditions ... -
Integrability of complex planar systems with homogeneous nonlinearities
(Elsevier, 2016)In this paper we obtain sufficient conditions for the existence of a local analytic first integral for a family of quintic systems having homogeneous nonlinearities. The family studied in this work is the largest one ... -
Integrability of Liénard systems with a weak saddle
(Springer International Publishing, 2017)We characterize the local analytic integrability of weak saddles for complex Lienard systems, x˙ = y−F(x), y˙ = ax, 0 = a ∈ C, with F analytic at 0 and F(0) = F (0) = 0. We prove that they are locally integrable at the ... -
Integrability of Lotka-Volterra planar complex cubic systems
(World Scientific, 2016)In this paper we study the Lotka-Volterra complex cubic systems. We obtain necessary conditions of integrability for these systems with some restriction on the parameters. The sufficiency is proved for all conditions, ... -
Integrability of planar nilpotent differential systems through the existence of an inverse integrating factor
(Elsevier, 2019)In this work is characterized the analytic integrability problem around a nilpotent singularity for differential systems in the plane under generic conditions. The analytic integrability problem is characterized via the ... -
Integrability of planar polynomial differential systems through linear differential equations
(Rocky Mountain Mathematics Consortium, 2006)In this work we consider rational ordinary differential equations dy/dx = Q(x, y)/P(x, y), with Q(x, y) and P(x, y) coprime polynomials with real coefficients. We give a method to construct equations of this type for ... -
Integrable zero-Hopf singularities and 3-dimensional centers
(2018-01-25)In this paper we show that the well-known Poincaré-Lyapunov nondegenerate analytic center problem in the plane and its higher dimensional version expressed as the 3-dimensional center problem at the zero-Hopf singularity ... -
Intra-specific association between carbon isotope composition and productivity in woody plants: A meta-analysis
(Elsevier, 2016)The study of intra-specific variations in growth and plant physiological response to drought is crucial to understand the potential for plant adaptation to global change. Carbon isotope composition (δ13C) in plant tissues ... -
Inverse Jacobi multiplier as a link between conservative systems and Poisson structures
(IOP Publishing, 2017-07-15)Some aspects of the relationship between conservativeness of a dynamical system (namely the preservation of a finite measure) and the existence of a Poisson structure for that system are analyzed. From the local point of ... -
Inverse Jacobi multipliers and first integrals for nonautonomous differential systems
(Springer Basel, 2015-05-01)In this paper we consider nonautonomous differential systems of arbitrary dimension and first find expressions for their inverse Jacobi multipliers and first integrals in some nonautonomous invariant set in terms of the ... -
Isogeny volcanoes of elliptic curves and sylow subgroups
(Springer International Publishing Switzerland, 2015)Given an ordinary elliptic curve over a finite field located in the floor of its volcano of ℓ-isogenies, we present an efficient procedure to take an ascending path from the floor to the level of stability and back to ... -
Iterated line digraphs are asymptotically dense
(Elsevier, 2017)We show that the line digraph technique, when iterated, provides dense digraphs, that is, with asymptotically large order for a given diameter (or with small diameter for a given order). This is a well-known result for ... -
Labeling constructions using digraph products
(Elsevier, 2013)In this paper we study the edge-magicness of graphs with equal size and order, and we use such graphs and digraph products in order to construct labelings of different classes and of different graphs. We also study super ... -
Lability and mobility effects on mixtures of ligands under steady-state conditions
(Royal Society of Chemistry, 2003)Analytical solutions for the steady-state flux arriving at an active surface from a mixture (in which one active species reacts with non-active ligands in the medium) can be helpful in a variety of problems: voltammetric ... -
Lability of complexes in steady-state finite planar diffusion
(Elsevier, 2006)The analytical solution of the reaction-diffusion problem of a species forming a complex (with any association and dissociation rate constants) in solution and disappearing at an active planar surface is presented for a ... -
Langford sequences and a product of digraphs
(Elsevier, 2016)Skolem and Langford sequences and their many generalizations have applications in numerous areas. The -product is a generalization of the direct product of digraphs. In this paper we use the -product and super edge-magic ...