Zobrazeno 1 - 10
of 19
pro vyhledávání: '"Massimo Villarini"'
Publikováno v:
Electronic Journal of Differential Equations, Vol 2004, Iss 128, Pp 1-14 (2004)
We prove a generalization of a theorem proved by Seifert and Fuller concerning the existence of periodic orbits of vector fields via the averaging method. Also we show applications of these results to Kepler motion and to geodesic flows on spheres.
Externí odkaz:
https://doaj.org/article/22c8904da9204297ba03c4ff83c0150f
Autor:
Rita Ceppitelli, Massimo Villarini
Publikováno v:
Le Matematiche, Vol 41, Iss 1,2, Pp 205-250 (1986)
The purpose of this paper is to obtain a theoretical estimate of the effect of a nonlinear perturbation on the solution of a boundary value problem for quasilinear hyperbolic systems in bicharacteristic canonic form with the same boundary data which
Externí odkaz:
https://doaj.org/article/b67e8777b5fc4bf4825388c561cfb975
Publikováno v:
Recercat. Dipósit de la Recerca de Catalunya
instname
Publicacions Matemàtiques; Vol. 49, Núm. 1 (2005); p. 197-212
ResearcherID
Scopus-Elsevier
Recercat: Dipósit de la Recerca de Catalunya
Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Dipòsit Digital de Documents de la UAB
Universitat Autònoma de Barcelona
instname
Publicacions Matemàtiques; Vol. 49, Núm. 1 (2005); p. 197-212
ResearcherID
Scopus-Elsevier
Recercat: Dipósit de la Recerca de Catalunya
Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Dipòsit Digital de Documents de la UAB
Universitat Autònoma de Barcelona
We present a geometric proof of the Poincaré-Dulac Normalization Theorem for analytic vector fields with singularities of Poincaré type. Our approach allows us to relate the size of the convergence domain of the linearizing transformation to the ge
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a304e406931c6e6afd6fc705387ac822
http://hdl.handle.net/2072/380061
http://hdl.handle.net/2072/380061
Autor:
Massimo Villarini
Publikováno v:
Ergodic Theory and Dynamical Systems. 39:257-288
We give an example of a$C^{\infty }$vector field$X$, defined in a neighbourhood$U$of$0\in \mathbb{R}^{8}$, such that$U-\{0\}$is foliated by closed integral curves of$X$, the differential$DX(0)$at$0$defines a one-parameter group of non-degenerate rota
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::10c53851dd0c0b2465d37b3b3cb4a108
https://doi.org/10.1017/etds.2017.20
https://doi.org/10.1017/etds.2017.20
Autor:
Massimo Villarini
Let Xe:S2n-1→TS2n-1 be a smooth perturbation of X0, the vector field associated to the dynamical system defined by n identical uncoupled harmonic oscillators constrained to their 1-energy level. We are dealing with the case when any orbit of every
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::aecc9905d762ec0227b8ba73f7183a2b
https://hdl.handle.net/11380/1265011
https://hdl.handle.net/11380/1265011
Autor:
Massimo Villarini
Publikováno v:
Journal of Mathematical Analysis and Applications. 373(2):521-534
We study families of holomorphic vector fields, holomorphically depending on parameters, in a neighborhood of an isolated singular point. When the singular point is in the Poincaré domain for every vector field of the family we prove, through a modi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::edb18cbe22cd92c8019fb72bb3827487
Autor:
Federica Sani, Massimo Villarini
Publikováno v:
Nonlinear Analysis: Theory, Methods & Applications. 73:3140-3150
Given a critical point of a C 2 -functional on a separable Hilbert space, we obtain sufficient conditions for it to be detectable (i.e. ‘visible’) from finite-dimensional Rayleigh–Ritz–Galerkin (RRG) approximations. While examples show that e
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2d552f57ea63cadcac7233d6f5010527
https://doi.org/10.1016/j.na.2010.06.086
https://doi.org/10.1016/j.na.2010.06.086
Autor:
Alessandro Margheri, Massimo Villarini
Publikováno v:
Journal of Dynamics and Differential Equations. 14:835-853
We study the problem of the existence and of the geometric structure of the set of periodic orbits of a vector field in presence of a first integral. We give a unified treatment and a geometric proof of existence results of periodic orbits by Moser (
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ac82e757b5cf4de8e9960b91b6e6766e
https://doi.org/10.1023/a:1020764611067
https://doi.org/10.1023/a:1020764611067
Autor:
Massimo Villarini
Publikováno v:
Annales de la faculté des sciences de Toulouse Mathématiques. 9:565-570
Nous etendons le Theoreme du Centre de Poincare-Lyapunov au cas non analytique: plus precisement nous demontrons qu'un champ de vecteurs de classe C k , k ≥ 3, avec un centre non degenere a l'origine est toujours C k-2 -orbitalement equivalent a sa
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d93f2768caf92b91928865898ae81417
https://doi.org/10.5802/afst.972
https://doi.org/10.5802/afst.972
Autor:
Massimo Villarini, Marcello Galeotti
Publikováno v:
Annali di Matematica Pura ed Applicata (1923 -). 161:299-313
We study autonomous systems in the plane of polynomial type. We obtain conditions for the existence of unbounded trajectories of such systems. As a consequence we prove that it does not exist a planar polynomial system of even degree with a global ce
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9ec598162407d7297c030e6a29af8c09
https://doi.org/10.1007/bf01759643
https://doi.org/10.1007/bf01759643