Ara es mostren els items 12-31 de 36

  • Global periodicity conditions for maps and recurrences via normal forms 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2013-11)
    Article
    Accés obert
    We face the problem of characterizing the periodic cases in parametric families of rational diffeomorphisms of K, where K is ℝ or ℂ, having a fixed point. Our approach relies on the Normal Form Theory, to obtain necessary ...
  • Global periodicity conditions for maps and recurrences via Normal Forms 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2012-05-04)
    Altres
    Accés obert
    We face the problem of characterizing the periodic cases in parametric families of (real or complex) rational diffeomorphisms having a fixed point. Our approach relies on the Normal Form Theory, to obtain necessary conditions ...
  • Identification of one-parameter bifurcations giving rise to periodic orbits, from their period function. 

    Gasull Embid, Armengol; Mañosa Fernández, Víctor; Villadelprat Yagüe, Jordi (Universitat Politècnica de Catalunya. Centre Internacional de Mètodes Numèrics en Enginyeria (CIMNE), 2009)
    Text en actes de congrés
    Accés obert
  • Integrability and non-integrability of periodic non-autonomous Lyness recurrences 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2013-12-01)
    Article
    Accés obert
    This paper studies non-autonomous Lyness-type recurrences of the form x n+2 = (a n + x n+1)/x n , where {a n } is a k-periodic sequence of positive numbers with primitive period k. We show that for the cases k {1, 2, 3, ...
  • Integrability and non-integrability of periodic non-autonomous Lyness recurrences 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2010-12-22)
    Altres
    Accés obert
    This paper studies non-autonomous Lyness type recurrences of the form x_{n+2}=(a_n+x_n)/x_{n+1}, where a_n is a k-periodic sequence of positive numbers with prime period k. We show that for the cases k in {1,2,3,6} the ...
  • Integrability and non-integrability of periodic non-autonomous Lyness recurrences (revised and enlarged version) 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2011-12-22)
    Altres
    Accés obert
    This paper studies non-autonomous Lyness type recurrences of the form xn+2 = (an+xn+1)=xn, where fang is a k-periodic sequence of positive numbers with primitive period k. We show that for the cases k 2 f1; 2; 3; 6g the ...
  • Limit cycles and Lie symmetries 

    Freire, Emilio; Gasull Embid, Armengol; Guillamon Grabolosa, Antoni (2005)
    Article
    Accés obert
    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 

    Gasull Embid, Armengol; Guillamon Grabolosa, Antoni (2005)
    Article
    Accés obert
    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 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2011-06-01)
    Report de recerca
    Accés obert
    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 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2012-12)
    Article
    Accés obert
    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 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2015-03-18)
    Report de recerca
    Accés obert
    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 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2015-11-15)
    Article
    Accés obert
    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 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2011-06-09)
    Article
    Accés obert
    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 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2010-08-08)
    Article
    Accés obert
    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 

    Lázaro Ochoa, José Tomás; Gasull Embid, Armengol; Torregrosa, Joan (2012-03)
    Article
    Accés obert
  • On two and three periodic Lyness difference equations 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2009-12-26)
    Report de recerca
    Accés obert
    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 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2017-01-20)
    Working paper
    Accés obert
    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 ...
  • Period function for perturbed isochronous centres 

    Freire, Emilio; Gasull Embid, Armengol; Guillamon Grabolosa, Antoni (2001)
    Article
    Accés obert
  • Periodic points, Lie symmetries and non-integrability of planar maps 

    Cima Mollet, Anna; Gasull Embid, Armengol; Mañosa Fernández, Víctor (2017-07-03)
    Presentació
    Accés obert
  • Phase portrait of Hamiltonian systems with homogeneous nonlinearities 

    Gasull Embid, Armengol; Guillamon Grabolosa, Antoni; Mañosa Fernández, Víctor (1999)
    Article
    Accés obert
    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 ...