Ara es mostren els items 24-32 de 32

    • Phase portraits of separable Hamiltonian systems 

      Guillamon Grabolosa, Antoni; Pantazi, Chara (Universidad de Sevilla, 2007-09)
      Text en actes de congrés
      Accés obert
      We study some generalizations of potential Hamiltonian systems $(H(x, y) = y^2 + F(x))$ with one degree of freedom. In particular, we are interested in Hamiltonian systems with Hamiltonian functions of type $H(x, y) = ...
    • Polynomial differential systems having a given Darbouxian first integral 

      Llibre Saló, Jaume; Pantazi, Chara (Elsevier, 2004)
      Article
      Accés obert
      The Darbouxian theory of integrability allows to determine when a polynomial differential system in C2 has a first integral of the kind f λ1 1 ···f λp p exp(g/h) where fi , g and h are polynomials in C[x, y], and λi ∈ C ...
    • Pràctiques de Minitab, problemes guia i preguntes d'autoavaluacions 

      Ferrer Biosca, Alberto; Pantazi, Chara; Serrat Piè, Carles (Universitat Politècnica de Catalunya, 2015-09-28)
      Apunts
      Accés obert
    • Qualitative study of a model with Rastall gravity 

      Pantazi, Chara; Llibre Saló, Jaume (2020-12-17)
      Article
      Accés obert
      We consider the Rastall theory for the flat Friedmann-Robertson-Walker Universe filled with a perfect fluid that satisfies a linear equation of state. The corresponding dynamical system is a two dimensional system of ...
    • Semiclassical quantification of some two degree of freedom potentials: A differential Galois approach 

      Acosta Humánez, Primitivo Belen; Lázaro Ochoa, José Tomás; Pantazi, Chara; Morales Ruiz, Juan José (2024-01-01)
      Article
      Accés obert
      In this work we explain the relevance of the Differential Galois Theory in the semiclassical (or WKB) quantification of some two degree of freedom potentials. The key point is that the semiclassical path integral quantification ...
    • Some inverse problems 

      Christopher, Colin; Llibre Saló, Jaume; Pantazi, Chara; Walcher, Sebastian (2011-07-06)
      Report de recerca
      Accés restringit per política de l'editorial
      The Darboux theory of integrability for planar polynomial di®erential equations is a classical ¯eld, with connections to Lie symmetries, di®erential algebra and other areas of mathematics. In the present paper we introduce ...
    • Symmetries of homogeneous cosmologies 

      Cotsakis, Spiros; Leach, P. G. L.; Pantazi, Chara (2004)
      Article
      Accés obert
      We reformulate the dynamics of homogeneous cosmologies with a scalar field matter source with an arbitrary self- interaction potential in the language of jet bundles and extensions of vector fields. In this framework, the ...
    • The Picard-Fuchs equations for complete hyperelliptic integrals of even order curves, and the actions of the generalized Neumann system 

      Fedorov, Yuri; Pantazi, Chara (2014-03-01)
      Article
      Accés obert
      We consider a family of genus 2 hyperelliptic curves of even order and obtain explicitly the systems of 5 linear ordinary differential equations for periods of the corresponding Abelian integrals of first, second, and third ...
    • Three-dimensional Lotka–Volterra systems with 3:-1:2-resonance 

      Aziz, Waleed; Christopher, Colin; Llibre Saló, Jaume; Pantazi, Chara (2021-08)
      Article
      Accés obert
      We study the local integrability at the origin of a nine-parameter family of three-dimensional Lotka–Volterra differential systems with (3:- 1:2)-resonance. We give necessary and sufficient conditions on the parameters of ...