A class of uniquely (strongly) clean rings

In this paper we call a ring R dr-clean if every element is the sum of an idempotent and an element in d(RR) where d(RR) is the intersection of all essential maximal right ideals of R. If this representation is unique (and the elements commute) for every element we call the ring uniquely (strongly) dr-clean. Various basic characterizations and properties of these rings are proved, and many extensions are investigated and many examples are given. In particular, we see that the class of dr-clean rings lies between the class of uniquely clean rings and the class of exchange rings, and the class of uniquely strongly dr-clean rings is a subclass of the class of uniquely strongly clean rings. We prove that R is dr-clean if and only if R/dr(RR) is Boolean and R/Soc(RR) is clean where Soc(RR) is the right socle of R.

A class of uniquely (strongly) clean rings

In this paper we call a ring R dr-clean if every element is the sum of an idempotent and an element in d(RR) where d(RR) is the intersection of all essential maximal right ideals of R. If this representation is unique (and the elements commute) for every element we call the ring uniquely (strongly) dr-clean. Various basic characterizations and properties of these rings are proved, and many extensions are investigated and many examples are given. In particular, we see that the class of dr-clean rings lies between the class of uniquely clean rings and the class of exchange rings, and the class of uniquely strongly dr-clean rings is a subclass of the class of uniquely strongly clean rings. We prove that R is dr-clean if and only if R/dr(RR) is Boolean and R/Soc(RR) is clean where Soc(RR) is the right socle of R.

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  • Anderson, F.W., Fuller, K.R: Rings and Categories of Modules. New York. Springer-Verlag 1974.
  • Baccella, G.: Exchange property and the natural preorder between simple modules over semi-Artinian rings. J. Algebra 253, 133–166 (2002).
  • Camillo, V.P., Khurana, D., Lam, T.Y., Nicholson, W.K., Zhou, Y.: Continuous modules are clean. J. Algebra 304, 94–111 (2006).
  • Camillo, V.P., Yu, H.P.: Exchange rings, units and idempotents. Comm. Algebra 22, 4737–4749 (1994).
  • Camillo, V.P., Yu, H.P.: Stable range one for rings with many idempotents. Trans. Amer. Math. Soc. 347, 3141–3147 (1995).
  • Chen, H.: On strongly J-clean rings. Comm. Algebra 38, 3790–3804 (2010).
  • Chen, J., Wang, Z., Zhou, Y.: Rings in which elements are uniquely the sum of an idempotent and a unit that commute. J. Pure Appl. Algebra 213, 215–223 (2009).
  • Haghany, A., Varadarajan, K.: Study of formal triangular matrix rings. Comm. Algebra 27, 5507–5525 (1999). Han, J., Nicholson, W.K.: Extensions of clean rings. Comm. Algebra 29, 2589–2595 (2001).
  • Handelman, D.: Perspectivity and cancellation in regular rings. J. Algebra 48, 1–16 (1977).
  • Khurana, D., Lam, T.Y.: Rings with internal cancellation. J. Algebra 284, 203–235 (2005).
  • Lee, T.K., Yi, Z., Zhou, Y.: An example of Bergman’s and the extension problem for clean rings. Comm. Algebra 36, 1413–1418 (2008).
  • Lee, T.K., Zhou, Y.: A class of exchange rings. Glasgow Math. J. 50, 509–522 (2008).
  • Nicholson, W.K.: Lifting idempotents and exchange rings. Trans. Amer. Math. Soc. 229, 269–278 (1977).
  • Nicholson, W. K., Varadarajan, K., Zhou, Y.: Clean endomorphism rings. Arch. Math. 83, 340–343 (2004).
  • Nicholson, W.K., Yousif, M.F.: Weakly continuous and C2 conditions. Comm. Algebra 29, 2429–2446 (2001). Nicholson, W.K., Zhou, Y.: Rings in which elements are uniquely the sum of an idempotent and a unit. Glasgow Math. J. 46, 227–236 (2004).
  • ¨ Ozcan, A.C ¸ ., Aydo˘ gdu, P.: A generalization of semiregular and almost principally injective rings. Algebra Coll. 17, 905–916 (2010).
  • Yousif, M.F., Zhou, Y.: Semiregular, semiperfect and perfect rings relative to an ideal. Rocky Mountain J. Math. 32, 1651–1671 (2002).
  • Yu, H.P.: On quasi-duo rings. Glasgow Math. J. 37, 21–31 (1995).
  • Zhou, Y.: Generalizations of perfect, semiperfect and semiregular rings. Algebra Colloq. 7, 305–318 (2000).