2 papers
math.FA2009
Almost invariant half-spaces of operators on Banach spaces
George Androulakis, Alexey I. Popov, Adi Tcaciuc +1
We introduce and study the following modified version of the Invariant Subspace Problem: whether every operator T on a Banach space has an almost invariant half-space, that is, a s…
math.FA2008
On Banach Spaces containing or
George Androulakis, Nigel Kalton, Adi Tcaciuc
We use the Gowers block Ramsey theorem to characterize Banach spaces containing isomorphs of (for some ) or .