Previous |  Up |  Next

Article

Keywords:
flat object; flat cover; variety; cosimplicial object
Summary:
Flat covers do not exist in all varieties. We give a necessary condition for the existence of flat covers and some examples of varieties where not all algebras have flat covers.
References:
[1] Adámek J., Rosický J.: Locally Presentable and Accessible Categories. Cambridge University Press, Cambridge, 1994. MR 1294136
[2] Bican L., El Bashir R., Enochs E.: All modules have flat cover. Bull. London Math. Soc. 33 (2001), 45-51. DOI 10.1017/S0024609301008104 | MR 1832549
[3] Borceux F., Rosický J.: On von Neumann varieties. Theory Appl. Categ. 13 (2004), 5-26. MR 2116320 | Zbl 1057.18004
[4] Borceux F., Rosický J.: Purity in algebra. Algebra Universalis 56 (2007), 17-35. DOI 10.1007/s00012-006-1977-x | MR 2280436 | Zbl 1116.08004
[5] Johnstone P.T.: Affine categories and naturally Malcev categories. J. Pure Appl. Algebra 61 (1989), 251-256. DOI 10.1016/0022-4049(89)90075-3 | MR 1027744
[6] Kilp M., Knauer U., Mikhalev A.V.: Monoids, Acts and Categories. Walter de Gruyter, New York, 2000. MR 1751666 | Zbl 0945.20036
[7] Rosický J.: Flat covers and factorizations. J. Algebra 263 (2002), 1-13. DOI 10.1016/S0021-8693(02)00043-1 | MR 1925005 | Zbl 1024.18002
[8] Rosický J.: On projectivity in locally presentable categories. J. Algebra 272 (2004), 701-710. DOI 10.1016/j.jalgebra.2003.09.014 | MR 2028077 | Zbl 1040.18008
Partner of
EuDML logo