Mathematics – Commutative Algebra
Scientific paper
2011-10-20
Mathematics
Commutative Algebra
Minor improvements to the results. 25 pages, comments welcome. Submitted
Scientific paper
We introduce an operation on modules over an $F$-finite ring of characteristic $p$. We call this operation \emph{tight interior}. While it exists more generally, in some cases this operation is equivalent to the Matlis dual of tight closure. Moreover, the interior of the ring itself is simply the big test ideal. We directly prove, without appeal to tight closure, results analogous to persistence, colon capturing, and working modulo minimal primes, and we begin to develop a theory dual to phantom homology. Using our dual notion of persistence, we obtain new and interesting transformation rules for tight interior, and so in particular for the test ideal, which complement the main results of a recent paper of the second author and K. Tucker. Using our theory of phantom homology, we prove a vanishing theorem for maps of Ext. We also compare our theory to M. Blickle's notion of Cartier modules, and in the process, we prove new existence results for Blickle's test submodule. Finally, we apply the theory we developed to the study of test ideals in non-normal rings, proving that the finitistic test ideal coincides with the big test ideal in some cases.
Epstein Neil
Schwede Karl
No associations
LandOfFree
A dual to tight closure theory does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A dual to tight closure theory, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A dual to tight closure theory will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-84550