To reduce to resolving Cohen–Macaulay singularities, Faltings initiated the program of “Macaulayfying” a given Noetherian scheme X. For wide class X, Kawasaki built sought-for modifications, with crucial drawback that his blowups did not preserve locus CM(X)?X, where X is already Cohen–Macaulay. We extend Kawasaki’s methods show every quasi-excellent, has X˜ proper map X˜?X an isomorphism over ...

A cohomological support, Supp A (M), is defined for finitely generated modules M over a left noetherian ring R, with respect to a ring A of central cohomology operations on the derived category of R-modules. It is proved that if the A-module Ext R (M, M) is noetherian and Ext R (M, R) = 0 for i ≫ 0, then every closed subset of Supp A (M) is the support of some finitely generated R-module. This ...

For a semigroup S (group G) we study relational equations and describe all semigroups with equationally Noetherian direct powers. It follows that any group G has powers if consider as an algebraic structure of certain language. Further specify the results follows: power finite is Noetherian, then minimal ideal Ker(S) rectangular band groups coincides set reducible elements

We characterize left Noetherian rings which have only trivial derivations.