We review some numerical methods for selfadjoint and nonselfadjoint boundary eigenvalue problems.

The JSJ decomposition encodes the automorphisms and virtually cyclic splittings of a hyperbolic group. For general finitely presented groups, only their splittings. In this sequence papers we study hierarchically group that satisfies some weak acylindricity conditions. To these construct an object can be viewed as higher rank decomposition. first paper demonstrate our construction in case right...