Electronic Journal of Differential Equations,
Vol. 2011 (2011), No. 124, pp. 1-6.

Title: Non-existence of limit cycles via inverse integrating factors

Authors: Leonardo Laura-Guarachi (Univ. Michoacana, Morelia, Mexico)
         Osvaldo Osuna           (Univ. Michoacana, Morelia, Mexico)
	 Gabriel Villasenor-Aguilar (Univ. Michoacana, Morelia, Mexico)

Abstract:
 It is known that if a planar differential systems has an inverse
 integrating factor, then all the limit cycles contained in the domain
 of definition of the inverse integrating factor are contained in
 the zero set of this function. Using this fact we give some
 criteria to rule out the existence of limit cycles.
 We also present some applications and examples that illustrate our
 results.

Submitted September 1, 2011. Published September 27, 2011.
Math Subject Classifications: 34C05, 34C07, 34C25.
Key Words: Algebraic set; integrating factors;
 inverse integrating factors; limit cycles.