Multiplicative Mappings of Rings

Autor: Fang Yan Lu, Jin Hai Xie
Rok vydání: 2006
Předmět:
Zdroj: Acta Mathematica Sinica, English Series. 22:1017-1020
ISSN: 1439-7617
1439-8516
DOI: 10.1007/s10114-005-0620-7
Popis: Let ℛ and \({\fancyscript S}\) be arbitrary associative rings. A mapping φ of ℛ onto \({\fancyscript S}\) is called a multiplicative isomorphism if φ is bijective and satisfies φ(xy) = φ(x)φ(y) for all x, y ∈ ℛ. In this short note, we establish a condition on ℛ, in the case where ℛ may not contain any non–zero idempotents, that assures that φ is additive, which generalizes the famous Martindale's result. As an application, we show that under a mild assumption every multiplicative isomorphism from the radical of a nest algebra onto an arbitrary ring is additive.
Databáze: OpenAIRE