Linear contraction mappings
Linear fractional transformations and companion matrices
Linear inessential operators and generalized inverses
The space of inessential bounded linear operators from one Banach space into another is introduced. This space, , is a subspace of which generalizes Kleinecke’s ideal of inessential operators. For certain subspaces of , it is shown that when has a generalized inverse modulo , then there exists a projection such that has a generalized inverse and .
Littlewood functions, Hankel multipliers and power bounded operators on a Hilbert space
Local behaviour of operators
Local polynomials are polynomials
We prove that a function f is a polynomial if G◦f is a polynomial for every bounded linear functional G. We also show that an operator-valued function is a polynomial if it is locally a polynomial.