Abstract
We investigate the relationship between projective modules and idempotent ideals for group rings, polynomial rings and more general rings, giving a survey of known results, proving some new results and raising a number of questions. In particular, it is proved that if R is any ring, X a projective right R-module and A an ideal of R such that the R-module X/XA can be generated by a set of elements of cardinality ℵ, for some infinite cardinal ℵ, then X/XB can be generated by a set of elements of cardinality ℵ, where B is the unique maximal idempotent ideal of R contained in A. A recurring theme is that of “intersection theorems” which give information about intersections of powers of ideals of the ring.
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For S.K.Jain on the occasion of his 70th birthday
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Smith, P.F. (2010). Projective Modules, Idempotent Ideals and Intersection Theorems. In: Van Huynh, D., López-Permouth, S.R. (eds) Advances in Ring Theory. Trends in Mathematics. Birkhäuser Basel. https://doi.org/10.1007/978-3-0346-0286-0_20
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