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arXiv · 0902.2273

Corings with decomposition and semiperfect corings

L. El Kaoutit·J. Gómez-Torrecillas
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Abstract

We give a characterization, in terms of Galois infinite comatrix corings, of the corings that decompose as a direct sum of left comodules which are finitely generated as left modules. Then we show that the associated rational functor is exact. This is the case of a right semiperfect coring which is locally projective and whose Galois comodule is a projective left unital module with superfluous radical.

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L. El Kaoutit, J. Gómez-Torrecillas. 2009-02-13. Corings with decomposition and semiperfect corings. https://arxiv.org/abs/0902.2273

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