On completeness of spaces of continuous functions
Let , 0 ≤ t ≤ 1, be Banach spaces obtained via complex interpolation. With suitable hypotheses, linear operators T that act boundedly on both and will act boundedly on each . Let denote such an operator when considered on , and denote its spectrum. We are motivated by the question of whether or not the map is continuous on (0,1); this question remains open. In this paper, we study continuity of two related maps: (polynomially convex hull) and (boundary of the polynomially convex...
In this paper we give a sufficient condition on the pair of weights for the boundedness of the Weyl fractional integral from into . Under some restrictions on and , this condition is also necessary. Besides, it allows us to show that for any there exist non-trivial weights such that is bounded from into itself, even in the case .
We prove a conjecture of Wojtaszczyk that for 1 ≤ p < ∞, p ≠ 2, does not admit any norm one projections with dimension of the range finite and greater than 1. This implies in particular that for 1 ≤ p < ∞, p ≠ 2, does not admit a Schauder basis with constant one.