Zobrazeno 1 - 10
of 74
pro vyhledávání: '"Nicolae VULPE"'
Publikováno v:
Electronic Journal of Differential Equations, Vol 2024, Iss 50,, Pp 1-38 (2024)
Externí odkaz:
https://doaj.org/article/917d5a89067f422d9ce461d2beba7079
Autor:
Nicolae Vulpe
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2024, Iss 22, Pp 1-68 (2024)
Consider the class ${\bf QS}$ of all non-degenerate planar quadratic differential systems and its subclass ${\bf QSP}$ of all its systems possessing an invariant parabola. This is an interesting family because on one side it is defined by an algebrai
Externí odkaz:
https://doaj.org/article/92fc0bc8551742cb8445fa48ef1a5727
Dynamics of the Isotropic Star Differential System from the Mathematical and Physical Point of Views
Publikováno v:
AppliedMath, Vol 4, Iss 1, Pp 70-78 (2024)
The following differential quadratic polynomial differential system dxdt=y−x, dydt=2y−yγ−12−γy−5γ−4γ−1x, when the parameter γ∈(1,2] models the structure equations of an isotropic star having a linear barotropic equation of state,
Externí odkaz:
https://doaj.org/article/307f6d92a26d4ed2a213caec9dfbf296
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2023, Iss 40, Pp 1-94 (2023)
In this article we consider the class $\textbf{CSL}_7^{2r2c \infty}$ of non-degenerate real planar cubic vector fields, which possess two real and two complex distinct infinite singularities and invariant straight lines of total multiplicity 7, inclu
Externí odkaz:
https://doaj.org/article/7d7d10fac83e4748b4a1893ea97fe913
Publikováno v:
Electronic Journal of Differential Equations, Vol 2021, Iss 83,, Pp 1-110 (2021)
Externí odkaz:
https://doaj.org/article/f9d7458f689b41e7a3d0fc976144095d
Autor:
Cristina Bujac, Nicolae Vulpe
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2017, Iss 85, Pp 1-35 (2017)
In the article [C. Bujac, J. Llibre, N. Vulpe, Qual. Theory Dyn. Syst. 15(2016), 327–348] for the family of cubic differential systems with the maximum number of invariant straight lines, i.e. 9 (considered with their multiplicities), the all first
Externí odkaz:
https://doaj.org/article/d648c42b4123403687c43f9283a3afd2
Publikováno v:
Electronic Journal of Differential Equations, Vol 2017, Iss 295,, Pp 1-122 (2017)
Let QSH be the whole class of non-degenerate planar quadratic differential systems possessing at least one invariant hyperbola. We classify this family of systems, modulo the action of the group of real affine transformations and time rescaling, acco
Externí odkaz:
https://doaj.org/article/50f3d6cbe0fa4cfbaeb1dde3644cdaea
Publikováno v:
Electronic Journal of Differential Equations, Vol 2016, Iss 162,, Pp 1-50 (2016)
In this article we consider the class QS of all non-degenerate quadratic systems. A quadratic polynomial differential system can be identified with a single point of R^{12} through its coefficients. In this paper using the algebraic invariant the
Externí odkaz:
https://doaj.org/article/2fdd1d42398141a684eedf95d9d277af
Autor:
Cristina Bujac, Nicolae Vulpe
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2015, Iss 74, Pp 1-38 (2015)
In this article we prove a classification theorem (Main theorem) of real planar cubic vector fields which possess two distinct infinite singularities (real or complex) and eight invariant straight lines, including the line at infinity and including t
Externí odkaz:
https://doaj.org/article/3b53c7bb35ca45709b8c54131d35d2a5
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2015, Iss 49, Pp 1-60 (2015)
In this article we obtain the geometric classification of singularities, finite and infinite, for the two subclasses of quadratic differential systems with total finite multiplicity $m_f=4$ possessing exactly three finite singularities, namely: syste
Externí odkaz:
https://doaj.org/article/2f556822df244efe9e5835c168dbfdbe