Finiteness Properties of Locally Finite Abelian Varieties
نویسندگان
چکیده
We show that any locally finite abelian variety is generated by a finite algebra. We solve a problem posed by D. Hobby and R. McKenzie by exhibiting a nonfinitely based finite abelian algebra.
منابع مشابه
Homological Finiteness of Abelian Covers
We present a method for deciding when a regular abelian cover of a finite CWcomplex has finite Betti numbers. To start with, we describe a natural parameter space for all regular covers of a finite CW-complex X, with group of deck transformations a fixed abelian group A, which in the case of free abelian covers of rank r coincides with the Grassmanian of r-planes in H1(X,Q). Inside this paramet...
متن کاملGeometric and Homological Finiteness in Free Abelian Covers
We describe some of the connections between the Bieri–Neumann– Strebel–Renz invariants, the Dwyer–Fried invariants, and the cohomology support loci of a space X. Under suitable hypotheses, the geometric and homological finiteness properties of regular, free abelian covers of X can be expressed in terms of the resonance varieties, extracted from the cohomology ring of X. In general, though, tran...
متن کاملMinimal Sets and Varieties
The aim of this paper is twofold. First some machinery is established to reveal the structure of abelian congruences. Then we describe all minimal, locally finite, locally solvable varieties. For locally solvable varieties, this solves problems 9 and 10 of Hobby and McKenzie. We generalize part of this result by proving that all locally finite varieties generated by nilpotent algebras that have...
متن کاملA Characterization of Decidable Locally Finite Varieties
We describe the structure of those locally finite varieties whose first order theory is decidable. A variety is a class of universal algebras defined by a set of equations. Such a class is said to be locally finite if every finitely generated member of the class is finite. It turns out that in order for such a variety to have a decidable theory it must decompose into the varietal product of thr...
متن کاملLocal finiteness for Green’s relations in semigroup varieties
A semigroup S is called locally finite (respectively, periodic) if each finitely generated (respectively, each monogenic) subsemigroup in S is finite. A semigroup variety is locally finite (respectively, periodic) if so are all its members. Clearly, every locally finite variety is periodic but the converse is not true. The issues related to determining extra properties that distinguish locally ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- IJAC
دوره 9 شماره
صفحات -
تاریخ انتشار 1999