How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Banach space
Definition
Let be a normed space in the sense of A norm on a real vector space, the induced metric, and the dictionary with the metric axioms, with induced metric . Then is a Banach space when this metric space is complete in the sense of Complete metric space: every Cauchy sequence converges in the space.
Equivalently: every Cauchy sequence in for the norm metric converges to a point of .
Remarks
- The metric is part of the data. Completeness is always completeness for the metric induced by the named norm.
- By Real and complex scalar conventions for normed spaces, the same definition is used over and over .
Depends on
Used by
- A one-sided comparison of two complete norms makes them equivalent Corollary
- Compact operator iff approximation numbers tend to zero Corollary
- Every finite-dimensional normed space is Banach Corollary
- Lambda identity minus compact has index zero Corollary
- Spectrum of a compact operator is countable with only zero as possible accumulation Corollary
- A closed subspace of ell-infinity that is not complemented Counterexample
- A complete domain is necessary for sequential uniform boundedness Counterexample
- Nearest-point maps to convex sets need not be linear Counterexample
- Weakly measurable need not be strongly measurable Counterexample
- Approximable operator Definition
- Approximation property and bounded approximation property Definition
- Banach algebra valued contour integral Definition
- Banach star-algebra without a required unit Definition
- Banach-valued simple function and integral Definition
- Banach-valued vector measure and variation Definition
- C k map between Banach spaces Definition
- C star algebra Definition
- Completion of a normed space Definition
- Complex sector and bounded analytic semigroup Definition
- Countable base Banach manifold and smooth map Definition
- Dissipative operator Definition
- Fréchet derivative between Banach spaces Definition
- Fredholm operator cokernel and index Definition
- Hilbert space Definition
- Infinitesimal generator of a C0-semigroup Definition
- Proper, coercive and weakly lower semicontinuous extended-real functionals Definition
- Reflexivity is surjectivity of the canonical map Definition
- Resolvent and spectrum of a closed operator on a Banach space Definition
- Schauder basis and coordinate functionals Definition
- Sectorial operator with the semigroup sign convention Definition
- Smooth Banach vector bundle and section Definition
- Spectrum and resolvent of a bounded operator Definition
- Strongly continuous semigroup Definition
- Uniformly convex Banach space Definition
- Unital Banach algebra Definition
- A projection with finite-dimensional kernel is Fredholm Example
- A regular level set in a Banach space Example
- C_b(X) is Banach for the supremum norm Example
- Coordinate partial sums on c₀ Example
- Diagonal operator on ell p is compact iff diagonal tends to zero Example
…and 79 more results.
Dependency tree · two levels
19 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- Theo Buhler and Dietmar A. Salamon, Functional Analysis (standard reference, not scraped)
- Gerald Teschl, Topics in Real and Functional Analysis (standard reference, not scraped)