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.
Measure-preserving transformations and systems
Definition
Let be a measure space. A measurable self-map is measure preserving if for every . The quadruple is a measure-preserving system; it is a probability system if . Here denotes an inverse image, whether or not is invertible. Neither completeness nor finiteness is implicit. The measure-space and measurable-map conventions are Measure spaces and A measurable function between measurable spaces.
Depends on
Used by
- An orientation-reversing homeomorphism need not be quasiconformal Counterexample
- The unitary dual need not be Hausdorff Counterexample
- Asymptotically mean stationary sources Definition
- Ergodic partial sums, time averages, and the invariant L2 subspace Definition
- Finite-alphabet stationary source Definition
- Invertible measure-preserving systems Definition
- Reiter's condition (P1) Definition
- Stationary process and canonical path shift Definition
- Strict and mod-null invariant sigma-algebras Definition
- Strong and weak mixing on a probability space Definition
- The Koopman operator Definition
- The one-dimensional torus and its normalized Haar integral Definition
- Unique ergodicity Definition
- A circle representation with an averaged orthogonal weight form Example
- A preserving permutation on two equal atoms Example
- A symmetric random walk on the circle Example
- Affine flux reduces the entropy semigroup to translation Example
- Compact groups have a constant Reiter net Example
- Matching C¹ pieces across a hyperplane have no jump derivative Example
- Newton shell theorem from harmonic mean values Example
- Opposed most powerful tests for two normal alternatives Example
- The positive-type Gaussian on the real line and its cyclic model Example
- False: Poincare recurrence needs no finite total measure False statement
- A Reiter net has an invariant-mean cluster point Lemma
- Averaging a Hermitian form unitarizes a finite-dimensional compact-group representation Lemma
- Haar averaging projects contractively onto the bounded intertwiners Lemma
- Monomial integrals on the sphere and orthonormality on the distinguished torus Lemma
- Monomials form complete orthogonal systems of the Bergman spaces of the disc, the ball and the polydisc Lemma
- No-return sets have disjoint null preimage towers Lemma
- Operators commuting with a generating family of multiplications Lemma
- The maximal ergodic inequality on a probability space Lemma
- Triangular averages of finite-past information converge to the infinite-past average Lemma
- Compact and locally compact abelian groups are amenable Proposition
- Compositions, iterates and completions preserve invariance Proposition
- A two-sided normal alternative need not have a UMP test Theorem
- Integral invariance under measure-preserving maps Theorem
- Isotypic projections are mutually orthogonal equivariant projections Theorem
- Iwasawa decomposition and Haar integration formula for SL2(R) Theorem
- Krylov–Bogolyubov existence of an invariant probability Theorem
- Measure preservation can be checked on a generating pi-system Theorem
…and 5 more results.
Dependency tree · two levels
4 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
- E–W Definition 2.1, pp.13–14 (standard reference, not scraped)