Abstract
Non-isomorphic direct decompositions of torsion-free Abelian groups are reflected in their endomorphism ring decompositions which admit matrix representations. The set of possible direct decompositions of a special kind matrix rings into direct sums of one-sided indecomposable ideals is described. This leads to the combinatorial constructions of isomorphisms between non-commutative differently decomposable ring structures.
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Funding
The research was supported by Russian Science Foundation (project no. 22-21-00267).
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Blagoveshchenskaya, E.A., Mikhalev, A.V. Matrix Representations of Endomorphism Rings for Torsion-Free Abelian Groups. Vestnik St.Petersb. Univ.Math. 56, 341–349 (2023). https://doi.org/10.1134/S1063454123030032
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DOI: https://doi.org/10.1134/S1063454123030032