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Morita context functors

Published online by Cambridge University Press:  24 October 2008

W. K. Nicholson
Affiliation:
Department of Mathematics and Statistics, University of Calgary, Calgary, Alberta, Canada, T2N 1N4
J. F. Watters
Affiliation:
Department of Mathematics, University of Leicester, Leicester, LEI 7RH

Abstract

Given a Morita context (R, V, W, S), there are functors W⊗() and hom (V, ) from R-mod to; S-mod and a natural transformation λ from the first to the second. This has an epi-mono factorization and the intermediate functor we denote by ()° with natural transformations and . The tensor functor is exact if and only if WR is flat, whilst the hom functor is exact if and only if RV is projective. We begin by determining conditions under which ()° is exact; this is Theorem 1.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1988

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