منابع مشابه
Stable Ranks for the Sarason
We prove a Corona type theorem with bounds for the Sarason algebra H∞ + C and determine its spectral characteristics, thus continuing a line of research initiated by N. Nikolski. We also determine the Bass, the dense, and the topological stable ranks of H∞ + C. To fix our setting, let A be a commutative unital Banach algebra with unit e and M(A) its maximal ideal space. The following concept of...
متن کاملOn the Ranks and Border Ranks of Symmetric Tensors
Motivated by questions arising in signal processing, computational complexity, and other areas, we study the ranks and border ranks of symmetric tensors using geometric methods. We provide improved lower bounds for the rank of a symmetric tensor (i.e., a homogeneous polynomial) obtained by considering the singularities of the hypersurface defined by the polynomial. We obtain normal forms for po...
متن کاملOn Higher Real and Stable Ranks for CCR C−algebras
We calculate the real rank and stable rank of CCR algebras which either have only finite dimensional irreducible representations or have finite topological dimension. We show that either rank of A is determined in a good way by the ranks of an ideal I and the quotient A/I in four cases: When A is CCR; when I has only finite dimensional irreducible representations; when I is separable, of genera...
متن کاملTarski’s Classes and Ranks
The terminology and notation used here have been introduced in the following articles: [9], [8], [7], [3], [4], [6], [5], [2], and [1]. For simplicity we adopt the following rules: W , X, Y , Z will denote sets, D will denote a non-empty set, f will denote a function, and x, y will be arbitrary. Let B be a set. We say that B is a Tarski-Class if and only if: for all X, Y such that X ∈ B and Y ⊆...
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 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: Communications in Algebra
سال: 2016
ISSN: 0092-7872,1532-4125
DOI: 10.1080/00927872.2016.1175606