Results 21 to 30 of about 375,845 (279)
Semicompleteness of homogeneous quadratic vector fields [PDF]
Annales de l'Institut Fourier, 2006 We investigate the quadratic homogeneous holomorphic vector fields on C n that are semicomplete, this is, those whose solutions are single-valued in their maximal definition domain. To a generic quadratic vector field we rationally associate some complex numbers that turn out to be integers in the semicomplete case, thus showing that the linear ...
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Delayed stability switches in singularly perturbed predator-prey models [PDF]
, 2016 In this paper we provide an elementary proof of the existence of canard solutions for a class of singularly perturbed predator-prey planar systems in which there occurs a transcritical bifurcation of quasi steady states.
Banasiak, J., Tchamga, M. S. Seuneu
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Harmonic crossover exponents in O(n) models with the pseudo-epsilon expansion approach [PDF]
, 2005 We determine the crossover exponents associated with the traceless tensorial quadratic field, the third- and fourth-harmonic operators for O(n) vector models by re-analyzing the existing six-loop fixed dimension series with pseudo-epsilon expansion ...
A. Aharony +16 more
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Oxygen nonstoichiometry and magnetic properties of doped manganites La0.7Sr0.3Mn0.95Fe0.05O3-δ [PDF]
Modern Electronic Materials, 2021 In this work, solid solutions of La0.7Sr0.3Mn0.95Fe0.05O3-δ with different oxygen content were obtained by the solid-phase reactions technique. Based on the investigation of the dynamics of changes in the oxygen index (3 – δ) during heating of the ...
Nikolay A. Kalanda +6 more
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Periodic perturbations of quadratic planar polynomial vector fields [PDF]
Anais da Academia Brasileira de Ciências, 2002 In this work are studied periodic perturbations, depending on two parameters, of quadratic planar polynomial vector fields having an infinite heteroclinic cycle, which is an unbounded solution joining two saddle points at infinity. The global study envolving infinity is performed via the Poincaré compactification.
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On the dualization of Born–Infeld theories
Physics Letters B, 2015 We construct a general Lagrangian, quadratic in the field strengths of n abelian gauge fields, which interpolates between BI actions of n abelian vectors and actions, quadratic in the vector field-strengths, describing Maxwell fields coupled to non ...
Laura Andrianopoli +2 more
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Uniqueness of limit cycles for quadratic vector fields
Discrete & Continuous Dynamical Systems - A, 2019 This article deals with the study of the number of limit cycles surrounding a critical point of a quadratic planar vector field, which, in normal form, can be written as $x'= a_1 x-y-a_3x^2+(2 a_2+a_5)xy + a_6 y^2$, $y'= x+a_1 y + a_2x^2+(2 a_3+a_4)xy -a_2y^2$.
Bravo, José Luis +3 more
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Spacetimes with vector distortion: Inflation from generalised Weyl geometry
Physics Letters B, 2016 Spacetime with general linear vector distortion is introduced. Thus, the torsion and the nonmetricity of the affine connection are assumed to be proportional to a vector field (and not its derivatives).
Jose Beltrán Jiménez, Tomi S. Koivisto
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Palatini formulation of the conformally invariant $$f\left( R,L_m\right) $$ f R , L m gravity theory
European Physical Journal C: Particles and Fields, 2022 We investigate the field equations of the conformally invariant models of gravity with curvature-matter coupling, constructed in Weyl geometry, using the Palatini formalism.
Tiberiu Harko, Shahab Shahidi
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Psi-series of quadratic vector fields on the plane [PDF]
Publicacions Matemàtiques, 1997 Psi-series (i.e., logarithmic series) for the solutions of quadratic vector fields on the plane are considered. Its existence and convergence is studied, and an algorithm for the location of logarithmic singularities is developed. Moreover, the relationship between psi-series and non-integrability is stressed and in particular it is proved that ...
Delshams Valdés, Amadeu, Mir, Arnau
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