Stiff well-posedness for hyperbolic systems with large relaxation terms (linear constant-coefficient problems)
The paper deals with the Cauchy problem for the linear constant-coefficient strongly hyperbolic system $u_t+Au_x=({1}/{delta})B$. The critical case where $B$ has a nontrivial nullspace is investigated. Under suitable assumptions on the matrices $A$ and $B$ the convergence in $L_2$ as $delta o 0$ of the solution $u(·,t,delta)$ of the Cauchy problem is proved. Then the evolution of the limit funct