mathematics, especially functional analysis, a Banach algebra, named after Stefan Banach, is an associative algebra A {\displaystyle A} over the real or complex...
17 KB (2,602 words) - 06:37, 23 September 2023
functional analysis, a Banach function algebra on a compact Hausdorff space X is unital subalgebra, A, of the commutative C*-algebra C(X) of all continuous...
2 KB (310 words) - 14:59, 14 June 2021
the term "Banach space" and Banach in turn then coined the term "Fréchet space". Banach spaces originally grew out of the study of function spaces by...
103 KB (17,214 words) - 08:06, 6 March 2024
mathematics, specifically in functional analysis, a C∗-algebra (pronounced "C-star") is a Banach algebra together with an involution satisfying the properties...
20 KB (2,829 words) - 11:21, 17 April 2024
In linear algebra, a sublinear function (or functional as is more often used in functional analysis), also called a quasi-seminorm or a Banach functional...
22 KB (4,213 words) - 16:45, 26 November 2023
Approximate identity (redirect from Σ-unital algebra)
a Banach algebra or ring (generally without an identity) that acts as a substitute for an identity element. A right approximate identity in a Banach algebra...
3 KB (474 words) - 21:29, 30 January 2023
Banach algebra Amenable Banach algebra Banach Jordan algebra Banach function algebra Banach *-algebra Banach algebra cohomology Banach bundle Banach bundle...
1 KB (125 words) - 15:40, 12 August 2022
operator algebra is usually used in reference to algebras of bounded operators on a Banach space or, even more specially in reference to algebras of operators...
5 KB (545 words) - 03:03, 6 May 2024
The Banach–Tarski paradox is a theorem in set-theoretic geometry, which states the following: Given a solid ball in three-dimensional space, there exists...
47 KB (6,697 words) - 17:38, 18 April 2024
with the uniform norm). Hence, it is, (by definition) a Banach function algebra. A uniform algebra A on X is said to be natural if the maximal ideals of...
2 KB (239 words) - 10:00, 13 January 2024
variables on Banach spaces. For a product space, the cylinder σ-algebra is the one that is generated by cylinder sets. In the context of a Banach space X ...
2 KB (244 words) - 16:41, 21 June 2023
trigonometric functions. The exponential function also has analogues for which the argument is a matrix, or even an element of a Banach algebra or a Lie algebra. The...
44 KB (5,859 words) - 14:44, 12 April 2024
by construction it becomes a uniform algebra and a commutative Banach algebra. By construction the disc algebra is a closed subalgebra of the Hardy space...
2 KB (241 words) - 00:22, 29 June 2022
Gelfand representation (redirect from C*-algebra representation)
of representing commutative Banach algebras as algebras of continuous functions; the fact that for commutative C*-algebras, this representation is an isometric...
12 KB (1,778 words) - 15:40, 12 February 2024
\|g\|.\,} Thus the Wiener algebra is a commutative unitary Banach algebra. Also, A(T) is isomorphic to the Banach algebra l1(Z), with the isomorphism...
4 KB (681 words) - 06:07, 10 June 2021
L-infinity (redirect from L∞ function)
gives them the structure of a Banach algebra, and in fact they are the standard examples of abelian Von Neumann algebras. The vector space ℓ ∞ {\displaystyle...
5 KB (764 words) - 01:02, 4 December 2023
\}\cup \{1\}} forms a basis for L2[0,1]. Basis (linear algebra) (Hamel basis) Schauder basis (in a Banach space) Dual basis Biorthogonal system (Markushevich...
3 KB (336 words) - 02:35, 22 July 2022
function taking values in a Banach space is a function that equals almost everywhere the limit of a sequence of measurable countably-valued functions...
3 KB (354 words) - 13:01, 15 August 2023
well-behaved Banach space. Functional analysis applies the methods of linear algebra alongside those of mathematical analysis to study various function spaces;...
64 KB (7,778 words) - 19:42, 15 May 2024
uniform convergence of functions on X . {\displaystyle X.} The space C ( X ) {\displaystyle {\mathcal {C}}(X)} is a Banach algebra with respect to this...
7 KB (1,108 words) - 22:17, 15 December 2022
abstractly as C*-algebras that have a predual; in other words the von Neumann algebra, considered as a Banach space, is the dual of some other Banach space called...
42 KB (5,923 words) - 00:34, 7 May 2024
homomorphism between algebraic structures is a function that is compatible with the operations of the structures. For all common algebraic structures, and...
16 KB (2,499 words) - 18:57, 19 February 2024
The Hahn–Banach theorem is a central tool in functional analysis. It allows the extension of bounded linear functionals defined on a vector subspace of...
77 KB (12,643 words) - 19:21, 19 April 2024
0\quad \forall u,v\in X.} Kachurovskii's theorem shows that convex functions on Banach spaces have monotonic operators as their derivatives. A subset G...
19 KB (2,397 words) - 19:37, 22 May 2024
the group algebra is any of various constructions to assign to a locally compact group an operator algebra (or more generally a Banach algebra), such that...
9 KB (1,319 words) - 06:11, 29 December 2023
inverse function theorem for complex holomorphic functions, for differentiable maps between manifolds, for differentiable functions between Banach spaces...
37 KB (6,894 words) - 05:50, 7 April 2024
In the mathematical field of functional analysis, Banach spaces are among the most important objects of study. In other areas of mathematical analysis...
2 KB (448 words) - 17:26, 9 February 2024
Stone–Weierstrass theorem (category Theory of continuous functions)
a Banach algebra, (that is, an associative algebra and a Banach space such that ‖fg‖ ≤ ‖f‖·‖g‖ for all f, g). The set of all polynomial functions forms...
26 KB (3,023 words) - 02:32, 25 May 2024
Gelfand–Mazur theorem (category Banach algebras)
isomorphic to the complex numbers, i. e., the only complex Banach algebra that is a division algebra is the complex numbers C. The theorem follows from the...
2 KB (270 words) - 06:52, 10 May 2021
the range of a function may refer to either of two closely related concepts: the codomain of the function, or the image of the function. In some cases...
6 KB (835 words) - 22:17, 19 December 2023