分野別セミナー

We give a certain energy decay rate for solutions
of the exterior initial-boundary value problem of
the nonlinear wave equations. We call our equation
as a nonlinear generalized Klein-Gordon equation
since the term $g(u)$ plays an essential role in
our argument. Note that concerning energy decay,
no result is known when both of $\rho(x,u_t)$ and
$g(u)$ are nonlinear.