We prove that pure morphisms of commutative rings are effective $A$-descent morphisms where $A$ is a (COMMUTATIVE RINGS)$^op$-indexed category given by (i) finitely generated modules, or (ii) flat modules, or (iii) finitely generated flat modules, or (iv) finitely generated projective modules.
Theory and Applications of Categories, Vol. 10, 2002, No. 9, pp 180-186 http://www.tac.mta.ca/tac/volumes/10/9/10-09.dvi http://www.tac.mta.ca/tac/volumes/10/9/10-09.ps http://www.tac.mta.ca/tac/volumes/10/9/10-09.pdf ftp://ftp.tac.mta.ca/pub/tac/html/volumes/10/9/10-09.dvi ftp://ftp.tac.mta.ca/pub/tac/html/volumes/10/9/10-09.psTAC Home