Mostrando ítems 19-38 de 39

• #### Limit cycles and Lie symmetries ﻿

(2005)
Artículo
Acceso abierto
Given a planar vector ﬁeld U which generates the Lie symmetry of some other vector ﬁeld X, we prove a new criterion to control the stability of the periodic orbits of U. The problem is linked to a classical problem ...
• #### Limit cycles for generalized Abel equations ﻿

(2005)
Artículo
Acceso abierto
This paper deals with the problem of finding upper bounds on the number of periodic solutions of a class of one-dimensional non-autonomous differential equations: those with the right-hand sides being polynomials of ...
• #### Non autonomous 2-periodic Gumovski-Mira difference equations ﻿

(2011-06-01)
Report de recerca
Acceso abierto
We consider two types of non-autonomous 2-periodic Gumovski-Mira difference equations. We show that while the corresponding autonomous recurrences are conjugated, the behavior of the sequences generated by the 2-periodic ...
• #### Non-autonomous two periodic Gumovski-Mira difference equations ﻿

(2012-12)
Artículo
Acceso abierto
We consider two types of nonautonomous two-periodic Gumovski–Mira difference equations. We show that while the corresponding autonomous recurrences are conjugated, the behavior of the sequences generated by the two-periodic ...
• #### Non-integrability of measure preserving maps via Lie symmetries ﻿

(2015-03-18)
Report de recerca
Acceso abierto
We consider the problem of characterizing, for certain natural number m, the local C^m-non-integrability near elliptic fixed points of smooth planar measure preserving maps. Our criterion relates this non-integrability ...
• #### Non-integrability of measure preserving maps via Lie symmetries ﻿

(2015-11-15)
Artículo
Acceso abierto
We consider the problem of characterizing, for certain natural number m, the local C^m-non-integrability near elliptic fixed points of smooth planar measure preserving maps. Our criterion relates this non-integrability ...
• #### On 2- and 3-periodic Lyness difference equations ﻿

(2011-06-09)
Artículo
Acceso abierto
We describe the sequences {xn}n given by the non-autonomous second-order Lyness difference equations xnþ2 ¼ ðan þ xnþ1Þ=xn, where {an}n is either a 2-periodic or a 3- periodic sequence of positive values and the initial ...
• #### On Poncelet's maps ﻿

(2010-08-08)
Artículo
Acceso abierto
Given two ellipses, one surrounding the other one, Poncelet introduced a map P from the exterior one to itself by using the tangent lines to the interior ellipse. This procedure can be extended to any two smooth, nested ...
• #### On the Chebyshev property for a new family of functions ﻿

(2012-03)
Artículo
Acceso abierto
• #### On two and three periodic Lyness difference equations ﻿

(2009-12-26)
Report de recerca
Acceso abierto
We describe the sequences {x_n}_n given by the non-autonomous second order Lyness difference equations x_{n+2}=(a_n+x_{n+1})/x_n, where {a_n}_n is either a 2-periodic or a 3-periodic sequence of positive values and the ...
• #### Parrondo's dynamic paradox for the stability of non-hyperbolic fixed points ﻿

(2017-01-20)
Working paper
Acceso abierto
We show that for periodic non-autonomous discrete dynamical systems, even when a common fixed point for each of the autonomous associated dynamical systems is repeller, this fixed point can became a local attractor for the ...
• #### Parrondo's dynamic paradox for the stability of non-hyperbolic fixed points ﻿

(2018-02)
Artículo
Acceso restringido por política de la editorial
We show that for periodic non-autonomous discrete dynamical systems, even when a common fixed point for each of the autonomous associated dynamical systems is repeller, this fixed point can became a local attractor for ...
• #### Period function for perturbed isochronous centres ﻿

(2001)
Artículo
Acceso abierto
• #### Periodic points, Lie symmetries and non-integrability of planar maps ﻿

(2017-07-03)
Presentación
Acceso abierto
• #### Periodic points of a Landen transformation ﻿

(2018-01-12)
Report de recerca
Acceso abierto
We prove the existence of 3-periodic orbits in a dynamical system associated to a Landen transformation previously studied by Boros, Chamberland and Moll, disproving a conjecture on the dynamics of this planar map introduced ...
• #### Phase portrait of Hamiltonian systems with homogeneous nonlinearities ﻿

(1999)
Artículo
Acceso abierto
The main goal of this work is to describe the phase portarit of Hamiltonian systems with a non degenerate center at the origin and homogeneous nonlinearities of arbitrary degree n. We apply our results to the case n=2 to ...
• #### Rational periodic sequences for the Lyness recurrence ﻿

(2010-04-30)
Otros
Acceso abierto
Consider the celebrated Lyness recurrence $x_{n+2}=(a+x_{n+1})/x_{n}$ with $a\in\Q$. First we prove that there exist initial conditions and values of $a$ for which it generates periodic sequences of rational numbers with ...
• #### The period function for Hamiltonian systems with homogeneous nonlinearities ﻿

(1996)
Artículo
Acceso abierto
The paper deals with Hamiltonian systems with homogeneous nonlinearities. We prove that such systems have no isochronous centers, that the period annulus of any of its centres is either bounded or the whole plane and that ...
• #### The period function for second-order quadratic ODEs is monotone ﻿

(2003)
Artículo
Acceso abierto
Very little is known about the period function for large families of centers. In one of the pioneering works on this problem, Chicone [?] conjectured that all the centers encountered in the family of second-order diﬀerential ...
• #### Upper bounds for the number of zeroes for some Abelian integrals ﻿

(2012-09)
Artículo
Acceso restringido por política de la editorial
Consider the vector field x′=−yG(x,y),y′=xG(x,y), where the set of critical points {G(x,y)=0} is formed by K straight lines, not passing through the origin and parallel to one or two orthogonal directions. We perturb it ...