An abstract ring which is isomorphic to the ring of all linear transformations of a vector space has been studied by wolfson. In this paper we follow his work and obtain a main theorem. Before formulating we first introduce the following.Definition: Let M be a (F, R)-module, i.e. M is a left F, right R-module, and let M' be a (K, R)-module, where F, K, R are rings. We say that M and M' are (ψ, I)isomorphic if there exists a mapping S satisfying the following conditions:(i) S is an isomorphism of (M, +) onto (M', +).(ii) There exists an isomorphism ψ of F onto K such that for all x ∈M, r ∈R we hav.e (fx)S = f~ψ(xS), (fxr)S = f~ψ(xS)r.Theorem: Let R be an abstract ring. Then R is isomorphic to the ring of linear transformations of a left vector space A over a division ring F if and only if the following conditions are satisfied:(i) R has a socle with and every non-zero ideal of R contains.(ii) Suppose that S_1⊕S_2,S_1 are minimal left ideals Of R, then(iii) R has an identity.Moreover, if R satisfies the above three conditions then every minimal right ideal A'= eR of R can be expressed as a left vector space over the division ring K and R is also the complete ring of K-linear transformations of A'. Furthermore there exists a (ψ, I)-isomorphism of A as (F, R)-module onto A' as (K, R)-module, and the rank of A is equal to that of Thus the left vector space of R except semi-linear transformation is uniquely determined by the soele.
A THEORY OF RINGS THAT ARE ISOMORPHIC TO THE COMPLETE RINGS OF LINEAR TRANSFORMATIONS(Ⅰ). Acta Mathematica Sinica, Chinese Series, 1979, 22(2): 204-218 https://doi.org/10.12386/A1979sxxb0018