Electronic Journal of Differential Equations,
Vol. 2002(2002), No. 08, pp. 1-12.

Title: On periodic solutions of superquadratic Hamiltonian systems
   
Author: Guihua Fei (Univ. of Minnesota, Duluth, MN, USA) 

Abstract:  
   We study the existence of periodic solutions for some 
   Hamiltonian systems $\dot z=JH_{z}(t,z)$ under new 
   superquadratic conditions which cover the case  
   $H(t,z)=|z|^{2}(\ln (1+|z|^{p}))^q $ with $p, q>1$.  
   By using the linking theorem, we obtain some new results.

Submitted September 20, 2001. Published January 15, 2002.
Math Subject Classifications: 58E05, 58F05, 34C25.
Key Words: periodic solution; Hamiltonian system; linking theorem.