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Hereditary semisimple classes

Published online by Cambridge University Press:  18 May 2009

W. G. Leavitt
Affiliation:
University of Nebraska
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It is well-known (see e.g. [1, p. 5]) that a class ℳ of (not necessarily associative) rings is the semisimple class for some radical class, relative to some universal class if and only if it has the following properties:

(a)if ℳ, then every non-zero ideal I of Rhas a non-zero homomorphic image I/J∈ℳ.

(b) If R but R∉ℳ, then R has a non-zero ideal I, where ℳ = {K| every non-zero K/H∉ℳ}. In fact ℳ is the radical class whose semisimple class is ℳ. On the other hand, if ℘ is a radical class, then ℐ℘ = {K/ if I is a non-zero ideal of K, then I∉℘} is its semisimple class. If a class ℳ is hereditary (that is, when R∈ℳ, then all its ideals are in ℳ), it clearly satisfies (a), but there do exist non-hereditary semisimple classes (see [2]). The condition (satisfied in all associative or alternative classes) is that ℘ is hereditary for a radical class ℘ if and only if ℘(I) ⊆ ℘(R) for all ideals I of all rings R [3, Lemma 2, p. 595].

Type
Research Article
Copyright
Copyright © Glasgow Mathematical Journal Trust 1970

References

REFERENCES

1.Divinsky, N. J., Rings and Radicals (Toronto, 1965).Google Scholar
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3.Anderson, T., Divinsky, N., and Sulińnski, A., Hereditary radicals in associative and alternative rings, Canad. J. Math. 17 (1965), 594603.CrossRefGoogle Scholar
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