In [[Spectralspectral theory]], for [[Unbounded_operator#Closed_linear_operators|closed linear operators]] which are not necessarily [[Self-adjoint operators|self-adjoint]], the set of '''normal eigenvalues''' is defined as a subset of the [[point spectrum]] <math>\sigma_p(A)</math> of <math>A</math> such that the space admits a decomposition into a direct sum of a finite-dimensional [[generalized eigenspace]] and an [[invariant subspace]] where <math>A-\lambda I</math> has a bounded inverse.
