Local quasi-isomorphisms of torsion free abelian groups
نویسندگان
چکیده
منابع مشابه
Jump degrees of torsion-free abelian groups
We show, for each computable ordinal α and degree a > 0(α), the existence of a torsion-free abelian group with proper αth jump degree a.
متن کاملUniquely Transitive Torsion-free Abelian Groups
We will answer a question raised by Emmanuel Dror Farjoun concerning the existence of torsion-free abelian groups G such that for any ordered pair of pure elements there is a unique automorphism mapping the first element onto the second one. We will show the existence of such a group of cardinality λ for any successor cardinal λ = μ+ with μ = μ0.
متن کاملQuasi-half-factorial Subsets of Abelian Torsion Groups
If G is an abelian torsion group with generating subset G0, then by a classical result in the theory of non-unique factorizations, the block monoid B(G0) is a half-factorial monoid if each of its atoms has cross number 1. In this case, G0 is called a half-factorial set. In this note, we introduce the notion of a k-quasihalf-factorial set and show for many abelian torsion groups that G0 k-quasi-...
متن کاملDegrees of orders on torsion-free Abelian groups
We show that if H is an effectively completely decomposable computable torsion-free abelian group, then there is a computable copy G of H such that G has computable orders but not orders of every (Turing) degree.
متن کاملOn the cotypeset of torsion-free abelian groups
In this paper the cotypeset of some torsion-free abelian groups of finite rank is studied. In particular, we determine the cotypeset of some rank two groups using the elements of their typesets. Introduction One of the important and known tools in the theory of torsion-free abelian groups is type and the typeset of a group. This set which is determined from the beginning of the the study the to...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Illinois Journal of Mathematics
سال: 1974
ISSN: 0019-2082
DOI: 10.1215/ijm/1256051005