The Root Closure of a Ring of Mixed Characteristic
نویسنده
چکیده
We define a closure operation for rings of mixed characteristic and verify that the closure is a ring. We then show that this closure produces a ring with good properties with respect to its Fontaine ring and give an example to show that rings that are not closed in this sense do not satisfy these properties.
منابع مشابه
ON THE EXISTENCE OF MAXIMAL COHEN-MACAULAY MODULES OVER p th ROOT EXTENSIONS
Let S be an unramified regular local ring having mixed characteristic p > 0 and R the integral closure of S in a pth root extension of its quotient field. We show that R admits a finite, birational module M such that depth(M) = dim(R). In other words, R admits a maximal Cohen-Macaulay module.
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تاریخ انتشار 2008