On image summand coinvariant modules and kernel summand invariant modules

On image summand coinvariant modules and kernel summand invariant modules

In this paper we introduce the concept of im-summand coinvariance and im-small coinvariance; that is, amodule M over a right perfect ring is said to be im-summand (im-small) coinvariant if, for any endomorphism φ of Psuch that Imφ is a direct summand (a small submodule) of P , φ(ker ) ker , where (P; ) is the projective cover ofM. We first give some fundamental properties of im-summand coinvariant modules and im-small coinvariant modules,and we prove that, for modules M and N over a right perfect ring such that N is a small epimorphic image of M, Mis N -im-summand coinvariant if and only if M is (im-coclosed) N -projective. Moreover, we introduce ker-summandinvariance and ker-essential invariance as the dual concept of im-summand coinvariance and im-small coinvariance,respectively, and show that, for modules M and N such that N is isomorphic to an essential submodule of M, M isN -ker-summand invariant if and only if M is (ker-closed) N -injective.

___

  • [1] Akalan E, Birkenmeier GF, Tercan A. Goldie extending modules. Communications in Algebra 2009; 37: 663-683.
  • [2] Baba Y, Oshiro K. Classical Artinian Rings and Related Topics. Hackensack, NJ, USA: World Scientific, 2009.
  • [3] Clark J, Lomp C, Vanaja N, Wisbauer R. Lifting Modules. Supplements and Projectivity in Module Theory. Frontiers in Mathematics. Boston, MA, USA: Birkhäuser, 2006.
  • [4] D’Este G, Keskin Tütüncü D. Pseudo projective modules which are not quasi projective and quivers. Taiwanese Journal of Mathematics 2018; 22: 1083-1090.
  • [5] Dickson SE, Fuller KR. Algebras for which every indecomposable right modules is invariant in its injective envelope. Pacific Journal of Mathematics 1969; 31: 655-658.
  • [6] Dung NV, Huynh DV, Smith PF, Wisbauer R. Extending Modules. Pitman Research Notes in Mathematics Series, Vol. 313. New York, NY, USA: Longman, 1994.
  • [7] Er N, Singh S, Srivastava AK. Rings and modules which are stable under automorphisms of their injective hulls. Journal of Algebra 2013; 379; 223-229.
  • [8] Ganesan L, Vanaja N. Strongly discrete modules. Communications in Algebra 2007; 35: 897-913.
  • [9] Guil Asensio PA, Keskin Tütüncü D, Kalebog̃az B, Srivastava AK. Modules which are coinvariant under automorphisms of their projective covers. Journal of Algebra 2016; 466: 147-152.
  • [10] Guil Asensio PA, Quynh TC, Srivastava AK. Additive unit structure of endomorphism rings and invariance of modules. Bulletin of Mathematical Sciences 2017; 7: 229-246.
  • [11] Izurdiaga MC. Supplement submodules and a generalization of projective modules. Journal of Algebra 2004; 277: 689-702.
  • [12] Jain SK, Singh S. Quasi-injective and pseudo-injective modules. Canadian Mathematical Bulletin 1975; 18 (3): 359-366.
  • [13] Johnson RE, Wong ET. Quasi-injective modules and irreducible rings. Journal of the London Mathematical Society 1961; 36: 260-268.
  • [14] Keskin Tütüncü D, Kuratomi Y. On epi-projective modules. East-West Journal of Mathematics 2008; 10 (1): 27-35.
  • [15] Keskin Tütüncü D, Kuratomi Y. On mono-injective modules and mono-ojective modules. Mathematical Journal of Okayama University 2013; 55: 117-129.
  • [16] Keskin Tütüncü D, Nematollahi MJ, Talebi Y. On H-supplemented modules. Algebra Colloquium 2011; 18: 915- 924.
  • [17] Kuratomi Y. Direct sums of H-supplemented modules. Journal of Algebra and Its Applications 2014; 13: 1350075.
  • [18] Kuratomi Y. On Goldie-extending modules with finite internal exchange property. Vietnam Journal of Mathematics 2016; 44: 315-328.
  • [19] Lee TK, Zhou Y. Modules which are invariant under automorphism of their injective hulls. Journal of Algebra and Its Applications 2013; 12: 1250159.
  • [20] Mohamed SH, Müller BJ. Continuous and Discrete Modules. London Mathematical Society Lecture Note Series 147. Cambridge, UK: Cambridge University Press, 1990.
  • [21] Oshiro K, Rizvi ST. The exchange property of quasicontinuous modules with the finite exchange property. Osaka Journal of Mathematics 1996; 33: 217-234.
  • [22] Singh S, Srivastava AK. Dual automorphism-invariant modules. Journal of Algebra 2012; 371: 262-275.
  • [23] Singh S, Srivastava AK. Rings of invariant module type and automorphism-invariant modules. Contemporary Mathematics 2014; 609: 299-311.
  • [24] Wisbauer R. Foundations of Module and Ring Theory. Reading, UK: Gordon and Breach, 1991.
  • [25] Wu LET, Jans JP. On quasi-projectives. Illinois Journal of Mathematics 1967; 11: 439-447.