Electronic Journal of Differential Equations,
Vol. 2002(2002), No. 26, pp. 1-13.

Title: Nonlinear Klein-Gordon equations coupled with Born-Infeld type equations
   
Authors: Pietro d'Avenia (Univ. degli Studi di Bari, Italy)
  Lorenzo Pisani (Univ. degli Studi di Bari, Italy)

Abstract: 
  In this paper we prove the existence of infinitely many 
  radially symmetric  standing waves in equilibrium with their own
  electro-magnetic field.  The interaction is described by means 
  of the minimal coupling rule; on the other hand the Lagrangian
  density for the electro-magnetic field is the second order 
  approximation of the Born-Infeld Lagrangian density.
 
Submitted November 14, 2001. Published March 4, 2002.
Math Subject Classifications: 58E15, 35J50, 35Q40, 35Q60.
Key Words: Nonlinear Klein-Gordon equation; solitary waves; 
           electromagnetic field; variational methods.