On almost-analytic functions, tensors and invariant subspaces
نویسندگان
چکیده
منابع مشابه
Almost Self-Bounded Controlled-Invariant Subspaces and Almost Disturbance Decoupling
The objective of this contribution is to characterize the so-called finite fixed poles of the Almost Disturbance Decoupling Problem by state feedback (ADDP) ′ . The most important step towards this result relies on the extension to almost invariant subspaces of the key notion of self-boundedness, as initially introduced by Basile and Marro for perfect controlled-invariants, namely, we introduce...
متن کاملSimply Invariant Subspaces and Generalized Analytic Functions1
for all/, g E A. Let A 0 be the set of functions in A with// dm = 0. Denote by Hpidm) the closure [^4]p of ^4 in Lpidm), p = i, 2 and by Haidm) the weak* closure |yl]* of A in P°°(¿wi). We shall drop the parenthesis (dm), in the future, while referring to Lpidm) Hpidm), etc. The functions in Hp we call generalized analytic functions. Say that a closed subspace ÜDÍ of Lp is simply invariant if [...
متن کاملInvariant Subspaces for the Backward Shift on Hilbert Spaces of Analytic Functions with Regular Norm
We investigate the structure of invariant subspaces of backward shift operator Lf = (f − f(0))/ζ on a large class of abstract Hilbert spaces of analytic functions on the unit disc where the forward shift operator Mζf = ζf acts as a contraction. Our main results show that under certain regularity conditions on the norm of such a space, the functions in a nontrivial invariant subspace of L have m...
متن کاملCharacteristic Functions and Joint Invariant Subspaces
Let T := [T1, . . . , Tn] be an n-tuple of operators on a Hilbert space such that T is a completely non-coisometric row contraction. We establish the existence of a “one-toone” correspondence between the joint invariant subspaces under T1, . . . , Tn, and the regular factorizations of the characteristic function ΘT associated with T . In particular, we prove that there is a non-trivial joint in...
متن کاملAnalytic Contractions, Nontangential Limits, and the Index of Invariant Subspaces
Let H be a Hilbert space of analytic functions on the open unit disc D such that the operator Mζ of multiplication with the identity function ζ defines a contraction operator. In terms of the reproducing kernel for H we will characterize the largest set ∆(H) ⊆ ∂D such that for each f, g ∈ H, g 6= 0 the meromorphic function f/g has nontangential limits a.e. on ∆(H). We will see that the question...
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: Tohoku Mathematical Journal
سال: 1962
ISSN: 0040-8735
DOI: 10.2748/tmj/1178244173