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Following this answer, let us make the following definition:

Definition: We say a comm ring $R$ has the "DIM property" iff for every prime ideal $p \subset R$, we have $$ \mathrm{dim}(R_p) + \mathrm{dim}(R/p) = \mathrm{dim}(R)\,. $$

  • The answer linked above says that $R$ of the following kinds of rings have the DIM property:

    • integral domains which are also algebra-finitely-generated over a field (or $\mathbb{Z}$; see this bachelor's thesis, page 1, (i) in the 2nd Theorem);

    • and, local Cohen-Macaulay rings.

  • (For completeness: the author of the 1st link above also cautions that catenary, even universally catenary, rings generally need not have the DIM property.)

I was wondering if anyone could suggest a source which discusses the details of the proofs of the above statements about the mentioned algebra-fin-gen domains, and local Cohen-Macaulay rings, having the DIM property?

Edit: Thanks to the comments below for providing these two references.

However, does anyone have a reference which specifically shows the DIM property for finite-gen algebras over $\mathbb{Z}$, not just fields?


Note: my motivation in considering this is Exercise 11.1.I of Vakil's Foundations of Algebraic Geometry; if I'm not mistaken this DIM property must be enforced on the values of the structure sheaf of $X$ on open sets.

For reference, the exercise is to prove:

If $X$ is a scheme, and $Y\subset X$ is an irreducible closed subset, and $\eta$ is the generic point corresponding to $Y$, then the codimension of $Y$ in $X$ equals the dimension of the stalk / local ring of $X$ at $\eta$.

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    You might find these stacks project pages helpful: https://stacks.math.columbia.edu/tag/00N7 and https://stacks.math.columbia.edu/tag/00OO – Alex Wertheim Jul 11 '22 at 03:43

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