The bass and topological stable ranks for algebras of almost periodic functions on the real line
نویسندگان
چکیده
Let Λ be a sub-semigroup of the reals. We show that the Bass and topological stable ranks of the algebras APΛ = {f ∈ AP : σ(f) ⊆ Λ} of almost periodic functions on the real line and with Bohr spectrum in Λ are infinite whenever the algebraic dimension of the Q-vector space generated by Λ is infinite. This extends Suárez’s result for APR = AP. Also considered are general subalgebras of AP. Introduction Let Cb(R,C) denote the set of bounded, continuous functions on R with values in C and let AP be the uniform closure in Cb(R,C) of the set of all functions of the form
منابع مشابه
On the boundedness of almost multipliers on certain Banach algebras
Almost multiplier is rather a new concept in the theory of almost functions. In this paper we discussion the boundedness of almost multipliers on some special Banach algebras, namely stable algebras. We also define an adjoint and extension for almost multiplier.
متن کاملOn the stable rank and reducibility in algebras of real symmetric func- tions
Let AR(D) denote the set of functions belonging to the disc algebra having real Fourier coefficients. We show that AR(D) has Bass and topological stable ranks equal to 2, which settles the conjecture made by Brett Wick in [18]. We also give a necessary and sufficient condition for reducibility in some real algebras of functions on symmetric domains with holes, which is a generalization of the m...
متن کاملStable Ranks of Banach Algebras of Operator-valued H Functions
Let E be an infinite-dimensional Hilbert space, and let H L(E) denote the Banach algebra of all functions f : D → L(E) that are holomorphic and bounded, equipped with the supremum norm ‖f‖∞ := supz∈D ‖f(z)‖L(E), f ∈ H ∞ L(E). We show that the Bass and topological stable ranks of H L(E) are infinite. If S is an open subset of T, then let A S L(E) denote the subalgebra of H L(E) of all functions ...
متن کاملSEMIGROUP ACTIONS , WEAK ALMOST PERIODICITY, AND INVARIANT MEANS
Let S be a topological semigroup acting on a topological space X. We develop the theory of (weakly) almost periodic functions on X, with respect to S, and form the (weakly) almost periodic compactifications of X and S, with respect to each other. We then consider the notion of an action of Son a Banach space, and on its dual, and after defining S-invariant means for such a space, we give a...
متن کاملThe Bass and Topological Stable Ranks of the Bohl Algebra Are Infinite
The Bohl algebra B is the ring of linear combinations of functions te on the real line, where k is any nonnegative integer, and λ is any complex number, with pointwise operations. We show that the Bass stable rank and the topological stable rank of B (where we use the topology of uniform convergence) are infinite.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2017