measure-preserving transformation

保测变换

Dynamical Systems · Graduate · Mathematics Resources editorial compilation (AI-assisted)

Other names / variants: m.p.t. · mpt

Translation evidence: Literature usage

Meaning in context

On a measure space (X,B,μ)(X,\mathcal B,\mu), a measurable self-map TT that satisfies μ(T−1A)=μ(A)\mu(T^{-1}A)=\mu(A) for all A∈BA\in\mathcal B.

测度空间上的可测自映射,保持每个可测集合原像的测度。

Example

The doubling map on the circle preserves length although it is not one-to-one.

Usage and distinctions

The transformation need not be invertible; preservation of the image measure of every set is a different assertion.

Definition sources

  1. Omri Sarig — Lecture Notes on Ergodic Theory§1.2, Definition 1.2, measurable and measure-preserving conditions · Checked 2026-10-14

Translation sources

  1. 朱子阳 — 算术动力系统:代数数论专题 VI(作者主页讲义)§1,定义1.1:保测变换 · Checked 2026-10-14

Original encyclopedia and terminology content: CC BY-SA 4.0. Contribute or report a correction.