Ciubotaru, StanislavCalin, Iurie2018-02-222018-02-222017CIUBOTARU, S., CALIN, Iu. The Lyapunov quantities and the GL (2 , R )-invariant center conditions for a class of bidimensional polynomial systems of differential equations with nonlinearities of the fourth degree. In: The Fourth Conference of Mathematical Society of the Republic of Moldova dedicated to the centenary of V. Andrunachievici (1917-1997): Proceeding CMSM4, June28-July2, 2017. Ch.: CEP USM, 2017, pp. 263-268. ISBN 978-9975-71-915-5.978-9975-71-915-5https://msuir.usm.md/handle/123456789/1650For the bidimensional polynomial systems of differential equations with nonlinearities of the fourth degree the recurent equations for determination of the Lyapunov quantities were established. Moreover, the general form of Lyapunov quantities for the mentioned systems were obtained. For a class of such systems the necessary and sufficient GL(2,R)-invariant conditions for the existence of center are given.enPolynomial differential systemsinvarianttransvectantLyapunov quantitiescenter conditionsArticle