Quasi-unmixed ring
In algebra,[] specifically in the theory of commutative rings, a quasi-unmixed ring is a Noetherian ring such that for each prime ideal p, the completion of the localization Ap is equidimensional, i.e. for each minimal prime ideal q in the completion, = the Krull dimension of Ap.
Equivalent conditions
A Noetherian integral domain is quasi-unmixed if and only if it satisfies Nagata's altitude formula.Precisely, a quasi-unmixed ring is a ring in which the unmixed theorem, which characterizes a Cohen–Macaulay ring, holds for integral closure of an ideal; specifically, for a Noetherian ring, the following are equivalent:
- is quasi-unmixed.
- For each ideal I generated by a number of elements equal to its height, the integral closure is unmixed in height.
- For each ideal I generated by a number of elements equal to its height and for each integer n > 0, is unmixed.