In the paper we consider the nonexistence of global solutions of the Cauchy problem for coupled Klein-Gordon equations of the form

In this paper the thermal transport phenomena in MEMS are investigated. The thermal Klein-Gordon transport equation for nanoscale structures is formulated and solved.

In this paper we prove the existence of a ground state solution for the nonlinear Klein-Gordon-Maxwell equations in the electrostatic case.

We describe a Lorentzian manifold, that is globally hyperbolic and geodesically complete, but such the (minimally coupled) Klein–Gordon operator with standard domain not essentially self-adjoint.