Quasi-normality of idempotents on nilpotents

We study the structure of idempotents in non-Abelian rings, concerning a ring property near to the normality of idempotents on the set of nilpotents. We call a ring with such property right idempotent-quasi-normalizing on nilpotents (simply, right IQNN), and study the structure of right IQNN rings in relation with matrix rings, polynomial ring, and factor rings, by which we extend the class of right IQNN rings. It is proved that the class of IQNN rings contains the $2$ by $2$ full matrix rings over fields and the upper triangular matrix rings over reduced rings. It is shown that given any countable field $K$, there exists a semiprime IQNN algebra $R$ over $K$ such that the polynomial ring $R[x]$ over $R$ is IQNN but not NI, and the upper nilradical of $R[x]$ is zero.

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  • [1] S.A. Amitsur, Radicals of polynomial rings, Canad. J. Math. 8, 355-361, 1956.
  • [2] R. Antoine, Nilpotent elements and Armendariz rings, J. Algebra 319, 3128-3140, 2008.
  • [3] G.F. Birkenmeier, H.E. Heatherly, and E.K. Lee, Completely prime ideals and associated radicals, in: Proc. Biennial Ohio State-Denison Conference 1992, edited by S.K. Jain and S.T. Rizvi, World Scientific, Singapore-New Jersey-London-Hong Kong, 102-129, 1993.
  • [4] W. Chen, On linearly weak Armendariz rings, J. Pure Appl. Algebra 219, 1122-1130, 2015.
  • [5] E.-K. Cho, T.K. Kwak, Y. Lee, Z. Piao, and Y. Seo, A structure of noncentral idempotents, Bull. Korean Math. Soc. 55, 25-40, 2018.
  • [6] Y. Chun, Y. C. Jeon, S. Kang, K. N. Lee, Y. Lee, A concept unifying the Armendariz and NI conditions, Bull. Korean Math. Soc. 48, 115-127, 2011.
  • [7] E.H. Feller, Properties of primary noncommutative rings, Trans. Amer. Math. Soc. 89, 79-91, 1958.
  • [8] K.R. Goodearl, Von Neumann Regular Rings, Pitman, London 1979.
  • [9] K.R. Goodearl and Jr. R.B.Warfield, An Introduction to Noncommutative Noetherian Rings, Cambridge University Press, Cambridge-New York-Port Chester-Melbourne- Sydney, 1989.
  • [10] C. Huh, H.K. Kim, and Y. Lee, p.p. rings and generalized p.p. rings, J. Pure Appl. Algebra 167, 37-52, 2002.
  • [11] S.U. Hwang, Y.C. Jeon, and Y. Lee, Structure and topological conditions of NI rings, J. Algebra 302, 186-199, 2006.
  • [12] H.K. Kim, T.K. Kwak, Y. Lee, and Y. Seo, Corrigendum Insertion of units at zero products [J. Algebra Appl. Vol. 17, 1850043 (20 pp), 2018], J. Algebra Appl. Vol. 17, 1892002, 2pp, 2018.
  • [13] N.K. Kim and Y. Lee, Armendariz rings and reduced rings, J. Algebra 223, 477-488, 2018.
  • [14] N.K. Kim, Y. Lee, and Y. Seo, Structure of idempotents in rings without identity, J. Korean Math. Soc. 51, 751-771, 2014.