Results 11 to 20 of about 6,930 (179)
Center conditions for a simple class of quintic systems [PDF]
International Journal of Mathematics and Mathematical Sciences, 2002 We obtained center conditions for an O-symmetric system of degree 5 for which the origin is a uniformly isochronous singular point.
Evgenii P. Volokitin
doaj +7 more sources
Isochronous centers of a linear center perturbed by fourth degree homogeneous polynomial
Bulletin des Sciences Mathématiques, 1999 The authors study plane time-reversible differential systems of the type \(\dot x= -y+ X_5(x,y)\), \(\dot y= x+ Y_5(x,y)\), where \(X_5\), \(Y_5\) are homogeneous polynomials of degree 5. They look for necessary and sufficient conditions for the origin to be an isochronous center.
Chavarriga, J., Giné, J., García, I.A.
openaire +4 more sources
Linearizability conditions of quasi-cubic systems
Electronic Journal of Qualitative Theory of Differential Equations, 2012 In this paper we study the linearizability problem of the two-dimensional complex quasi-cubic system $\dot{z}=z+(zw)^{d}(a_{30}z^{3}+a_{21}z^{2}w+a_{12}zw^2+a_{03}w^{3}),~\dot{w}=-w-(zw)^{d}(b_{30}w^{3}+b_{21}w^{2}z+b_{12}wz^2+b_{03}z^{3})$, where $z, w,
Wentao Huang, Xingyu Fan, Xingwu Chen
doaj +1 more source
Linearization of Isochronous Centers
Journal of Differential Equations, 1995 The authors propose a unified technique for the study of the isochronicity of polynomial systems. They first construct the linearizing changes of coordinates for isochronous systems having rational first integrals, namely for quadratic systems, for cubic systems symmetric with respect to a center and for reduced Kukles systems.
Mardesic, P., Rousseau, C., Toni, B.
openaire +2 more sources
Centers and isochronous centers for generalized quintic systems
Journal of Computational and Applied Mathematics, 2015 Agraïments: The first author is partially supported by FEDER-UNAB10-4E-378. The third author has been supported by FCT (grant PTDC/MAT/117106/2010 and through CAMGSDgrant number PEst-OE/EEI/LA0009/2013) In this paper we classify the centers and the isochronous centers of certain polynomial differential systems in R2 of degree d ≥ 5 odd that incomplex ...
Jaume Giné, Jaume Llibre, Claudia Valls
openaire +8 more sources
Tephrostratigraphy of Jurassic-Cretaceous boundary beds of Western Siberia
Russian Journal of Earth Sciences, 2022 The age of tuffaceous interlayers, represented by tuffs and tuffites, which are common in the Upper Jurassic-Lower Cretaceous deposits of Western Siberia (the Bazhenovo, Tutleim and Frolov Formations), is discussed.
Panchenko Ivan Vladimirovich +4 more
doaj +1 more source
Uniform isochronous cubic and quartic centers: Revisited
Journal of Computational and Applied Mathematics, 2017 In this paper we completed the classification of the phase portraits in the Poincaré disc of uniform isochronous cubic and quartic centers previously studied by several authors. There are three and fourteen different topological phase portraits for the uniform isochronous cubic and quartic centers respectively.
Artés Ferragud, Joan Carles +2 more
openaire +7 more sources
Phase Portraits of Uniform Isochronous Centers with Homogeneous Nonlinearities [PDF]
Journal of Dynamical and Control Systems, 2021 We classify the phase portraits in the Poincaré disc of the differential equations of the form x' = - y + xf(x, y), ẏ = x + yf(x, y) where f(x,y) is a homogeneous polynomial of degree n - 1 when n = 2, 3, 4, 5, and f has only simple zeroes. We also provide some general results on these uniform isochronous centers for all n ≥ 2.
Llibre, Jaume, Valls, Claudia
openaire +3 more sources
On the Limit Cycles for Continuous and Discontinuous Cubic Differential Systems
Discrete Dynamics in Nature and Society, 2016 We study the number of limit cycles for the quadratic polynomial differential systems x˙=-y+x2, y˙=x+xy having an isochronous center with continuous and discontinuous cubic polynomial perturbations.
Ziguo Jiang
doaj +1 more source
Significance of functional organization of settlements for development of primary rural settlements in the City of Zaječar [PDF]
Zbornik radova Departmana za geografiju, turizam i hotelijerstvo, 2020 The aim of this paper is determination of the City of Zaječar settlements' functional organization characteristics significant for development of primary rural settlements on this territory.
Popović Vladimir
doaj