Global solutions of coupled Klein-Gordon equations with different velocities in four space-time dimensions

Abstract

In this article one will discuss the system of coupled nonlinear Klein-Gordon equations with different velocities and different masses. The nonlinearity considered is a general quadratic nonlinearity without any restriction. The method is a classical boot-strap argument combined with a serious of techniques including conformal energy estimate, global sobolev's lemma and Hardy type inequalities.

This paper has been withdrawn by the author due to a crucial sign error in energy estimate