Definition:Inner Jordan Content
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Definition
Let $M \subseteq \R^n$ be a bounded subspace of Euclidean $n$-space.
Let:
- $\ds R = \prod_{i \mathop = 1}^n \closedint {a_i} {b_i}$
be a closed $n$-rectangle that contains $M$.
Let $V_R \in \R_{\ge 0}$ be defined as:
- $\ds V_R = \prod_{i \mathop = 1}^n \paren {b_i - a_i}$
The inner Jordan content of $M$ is defined and denoted as:
- $\map {m_*} M = V_R - \map {m^*} {R \setminus M}$
where:
- $\map {m^*} {R \setminus M}$ denotes the outer Jordan content of $R \setminus M$
That is, the inner Jordan content of $M$ is defined to be the outer Jordan content of the complement of $M$, relative to some fixed $R \supseteq M$.
This article, or a section of it, needs explaining. In particular: It appears that we have to pick some arbitrary $R$ before we can define the inner Jordan content. Hence it needs to be clarified that it doesn't matter what the exact details of $R$ are, as long as it contains $M$, the inner Jordan content is the same whatever $R$ is. Is this correct? If so, we need to add a section explaining this, because it is not obvious. Presumably Inner Jordan Content is Well-Defined is going to take on the job of proving it, but it's still worth adding the note of explanation. You can help $\mathsf{Pr} \infty \mathsf{fWiki}$ by explaining it. To discuss this page in more detail, feel free to use the talk page. When this work has been completed, you may remove this instance of {{Explain}} from the code. |
Also see
- Results about inner Jordan content can be found here.
Source of Name
This entry was named for Marie Ennemond Camille Jordan.
Sources
- 1994: A. Shenitzer and J. Steprans: The Evolution of Integration (Amer. Math. Monthly Vol. 101, no. 1: pp. 66 – 72) www.jstor.org/stable/2325128
- Derwent, John. "Jordan Measure." From MathWorld--A Wolfram Web Resource, created by Eric W. Weisstein. https://mathworld.wolfram.com/JordanMeasure.html