Uniquely Transitive Torsion-free Abelian Groups
نویسندگان
چکیده
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.
منابع مشابه
Groups in Which Commutativity Is a Transitive Relation
We investigate the structure of groups in which commutativity is a transitive relation on non-identity elements (CT-groups). A detailed study of locally nite, polycyclic, and torsion-free solvable CT-groups is carried out. Other topics include xed-point-free groups of automorphisms of abelian tor-sion groups and their cohomology groups.
متن کاملNormal edge-transitive Cayley graphs on the non-abelian groups of order $4p^2$, where $p$ is a prime number
In this paper, we determine all of connected normal edge-transitive Cayley graphs on non-abelian groups with order $4p^2$, where $p$ is a prime number.
متن کاملCotorsion theories cogenerated by א1-free abelian groups
Given an א1-free abelian group G we characterize the class CG of all torsion abelian groups T satisfying Ext(G, T ) = 0 assuming the special continuum hypothesis CH. Moreover, in Gödel’s constructable universe we prove that this characterizes CG for arbitrary torsion-free abelian G. It follows that there exist some ugly א1-free abelian groups.
متن کاملSome ugly א1-free abelian groups
Given an א1-free abelian group G we characterize the class CG of all torsion abelian groups T satisfying Ext(G, T ) = 0 assuming the special continuum hypothesis CH. Moreover, in Gödel’s constructable universe we prove that this characterizes CG for arbitrary torsion-free abelian G. It follows that there exist some ugly א1-free abelian groups.
متن کاملThe Classification Problem for S-local Torsion-free Abelian Groups of Finite Rank
Suppose that n ≥ 2 and that S, T are sets of primes. Then the classification problem for the S-local torsion-free abelian groups of rank n is Borel reducible to the classification problem for the T -local torsion-free abelian groups of rank n if and only if S ⊆ T .
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 2004