Diagonalizzazione periferica finita ed operatori perifericamente compatti

Summary The partial diagonalizability of a linear and continuous operator on a complex Banach space with respect to the elements of its peripheral spectrum is studied and some conditions that are related to such a decomposition are explored; some examples are given to specify the connections between these conditions. The concept of peripheral compactness of a linear and continuous operator is also introduced and several properties of such operators are studied.