The structure of almost-invariant half-spaces for some operators
نویسندگان
چکیده
منابع مشابه
Almost Invariant Half-spaces of Algebras of Operators
Given a Banach space X and a bounded linear operator T on X, a subspace Y of X is almost invariant under T if TY ⊆ Y + F for some finite-dimensional “error” F . In this paper, we study subspaces that are almost invariant under every operator in an algebra A of operators acting on X. We show that if A is norm closed then the dimensions of “errors” corresponding to operators in A must be uniforml...
متن کاملsome properties of fuzzy hilbert spaces and norm of operators
in this thesis, at first we investigate the bounded inverse theorem on fuzzy normed linear spaces and study the set of all compact operators on these spaces. then we introduce the notions of fuzzy boundedness and investigate a new norm operators and the relationship between continuity and boundedness. and, we show that the space of all fuzzy bounded operators is complete. finally, we define...
15 صفحه اولComposition Operators Acting between Some Weighted Möbius Invariant Spaces
In this paper we investigate conditions under which a holomorphic self-map of the unit disk induces a composition operator Cφ with closed range on the weighted Bloch space Blog. Also, we introduce a new class of functions the so called Flog(p, q, s) spaces. Necessary and sufficient conditions are given for a composition operator Cφ to be bounded and compact from Blog to Flog(p, q, s). Moreover,...
متن کاملAn invariant for pairs of almost commuting unbounded operators
For a wide class of pairs of unbounded selfadjoint operators (A,B) with bounded commutator and with operator (1+A2+B2)−1 being compact we construct aK-theoretical integer invariant ω(A,B), which is continuous, is equal to zero for commuting operators and is equal to one for the pair (x,−i d/dx). Such invariants in the case of bounded operators were constructed by T. Loring [1, 3] for matrices r...
متن کاملSOME PROPERTIES OF FUZZY HILBERT SPACES AND NORM OF OPERATORS
In the present paper we define the notion of fuzzy inner productand study the properties of the corresponding fuzzy norm. In particular, it isshown that the Cauchy-Schwarz inequality holds. Moreover, it is proved thatevery such fuzzy inner product space can be imbedded in a complete one andthat every subspace of a fuzzy Hilbert space has a complementary subspace.Finally, the notions of fuzzy bo...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Functional Analysis
سال: 2014
ISSN: 0022-1236
DOI: 10.1016/j.jfa.2014.07.007