Warfield invariants in Abelian group algebras
نویسنده
چکیده
LetF be a field of characteristic p 6= 0 andG an Abelian group. For each prime q and each ordinal α we calculate in terms of G and its sections the Warfield q-invariantsWα,q(V (FG)) of the group V (FG) of all normalized units in the commutative group algebra FG when either q = p,Gt/Gp is infinite and F is perfect, orG is p-mixed. Surprisingly, these invariants do not depend on F . This supplies recent result of ours in [3].
منابع مشابه
The Duals of Warfield
A Warreld group is a direct summand of a simply presented abelian group. In this paper, we describe the Pon-trjagin dual groups of Warreld groups, both for the p-local and the general case. A variety of characterizations of these dual groups is obtained. In addition, numerical invariants are given that distinguish between two such groups which are not topologically isomorphic.
متن کاملExistence Theorems for Warfield Groups
Warfield studied p-local groups that are summands of simply presented groups, introducing invariants that, together with Ulm invariants, determine these groups up to isomorphism. In this paper, necessary and sufficient conditions are given for the existence of a Warfield group with prescribed Ulm and Warfield invariants. It is shown that every Warfield group is the direct sum of a simply presen...
متن کاملC*-algebras on r-discrete Abelian Groupoids
We study certain function algebras and their operator algebra completions on r-discrete abelian groupoids, the corresponding conditional expectations, maximal abelian subalgebras (masa) and eigen-functionals. We give a semidirect product decomposition for an abelian groupoid. This is done through a matched pair and leads to a C*-diagonal (for a special case). We use this decomposition to study ...
متن کاملVarious topological forms of Von Neumann regularity in Banach algebras
We study topological von Neumann regularity and principal von Neumann regularity of Banach algebras. Our main objective is comparing these two types of Banach algebras and some other known Banach algebras with one another. In particular, we show that the class of topologically von Neumann regular Banach algebras contains all $C^*$-algebras, group algebras of compact abelian groups and ...
متن کاملComputational Method for Obtaining Filiform Lie Algebras of Arbitrary Dimension
This paper shows a new computational method to obtain filiform Lie algebras, which is based on the relation between some known invariants of these algebras and the maximal dimension of their abelian ideals. Using this relation, the law of each of these algebras can be completely determined and characterized by means of the triple consisting of its dimension and the invariants z1 and z2. As exam...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2008