• The period function for second-order quadratic ODEs is monotone 

    Gasull Embid, Armengol; Guillamon Grabolosa, Antoni; Villadelprat Yagüe, Jordi (2003)
    Acceso abierto
    Very little is known about the period function for large families of centers. In one of the pioneering works on this problem, Chicone [?] conjectured that all the centers encountered in the family of second-order differential ...