2 citations · 2 across the 5 of their papers we have counts for
5 papers
An inverse approach to the center-foci problem
Rafael Ramírez, Valentín Ramírez
The classical Center-Focus Problem posed by H. Poincaré in 1880's is concerned on the characterization of planar polynomial vector fields $X=(-y+P(x,y))\dfrac{\partial}{\partial x}…
A family of quadratic polynomial differential systems with algebraic solutions of arbitrary high degree
R. Ramírez, V. Ramírez
We show that the algebraic curve where and are polynomial of degree 1 and 2 respectively and is a polynomial solution of th…
A new approach to the vakonomic mechanics
J. Llibre, R. Ramírez, N. Sadovskaia
The aim of this paper is to show that the Lagrange-d'Alembert and its equivalent the Gauss and Appel principle are not the only way to deduce the equations of motion of the nonholo…
Quadratic vector fields with invariant algebraic curve of large degree
R. Ramirez, N. Sadovskaia
We construct a polynomial planar vector field of degree two with one invariant algebraic curves of large degree. We exhibit an explicit quadratic vector fields which invariant curv…
Cartesian approach for constrained mechanical system with three degree of freedom
Rafael Ramirez, Natalia Sadovskaia
In the history of mechanics, there have been two points of view for studying mechanical systems: The Newtonian and the Cartesian. According the Descartes point of view, the motion…