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Basic subgroups in modular abelian group algebras

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Abstract

Suppose F is a perfect field of char F = p ≠ 0 and G is an arbitrary abelian multiplicative group with a p-basic subgroup B and p-component G p . Let FG be the group algebra with normed group of all units V(FG) and its Sylow p-subgroup S(FG), and let I p (FG; B) be the nilradical of the relative augmentation ideal I(FG; B) of FG with respect to B.

The main results that motivate this article are that 1 + I p (FG; B) is basic in S(FG), and B(1 + I p (FG; B)) is p-basic in V(FG) provided G is p-mixed. These achievements extend in some way a result of N. Nachev (1996) in Houston J. Math. when G is p-primary. Thus the problem of obtaining a (p-)basic subgroup in FG is completely resolved provided that the field F is perfect.

Moreover, it is shown that G p (1 + I p (FG; B))/G p is basic in S(FG)/G p , and G(1 + I p (FG; B))/G is basic in V(FG)/G provided G is p-mixed.

As consequences, S(FG) and S(FG)/G p are both starred or divisible groups.

All of the listed assertions enlarge in a new aspect affirmations established by us in Czechoslovak Math. J. (2002), Math. Bohemica (2004) and Math. Slovaca (2005) as well.

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References

  1. D. O. Cutler: Another summable C Ω-group. Proc. Amer. Math. Soc. 26 (1970), 43–44.

    Article  MATH  MathSciNet  Google Scholar 

  2. P. V. Danchev: Topologically pure and basis subgroups in commutative group rings. Compt. Rend. Acad. Bulg. Sci. 48 (1995), 7–10.

    MATH  MathSciNet  Google Scholar 

  3. P. V. Danchev: Commutative group algebras of σ-summable abelian groups. Proc. Amer. Math. Soc. 125 (1997), 2559–2564.

    Article  MATH  MathSciNet  Google Scholar 

  4. P. V. Danchev: C λ-groups and λ-basic subgroups in modular group rings. Hokkaido Math. J. 30 (2001), 283–296.

    MATH  MathSciNet  Google Scholar 

  5. P. V. Danchev: Basic subgroups in abelian group rings. Czechoslovak Math. J. 52 (2002), 129–140.

    Article  MATH  MathSciNet  Google Scholar 

  6. P. V. Danchev: Basic subgroups in commutative modular group rings. Math. Bohem. 129 (2004), 79–90.

    MATH  MathSciNet  Google Scholar 

  7. P. V. Danchev: Subgroups of the basic subgroup in a modular group ring. Math. Slovaca 55 (2005), 431–441.

    MATH  MathSciNet  Google Scholar 

  8. P. V. Danchev: Sylow p-subgroups of commutative modular and semisimple group rings. Compt. Rend. Acad. Bulg. Sci. 54 (2001), 5–6.

    Google Scholar 

  9. L. Fuchs: Infinite abelian groups, I. Mir, Moscow, 1974. (In Russian.)

    Google Scholar 

  10. P. D. Hill: A summable C Ω-group. Proc. Amer. Math. Soc. 23 (1969), 428–430.

    Article  MATH  MathSciNet  Google Scholar 

  11. G. Karpilovsky: Unit groups of group rings. North-Holland, Amsterdam, 1989.

    MATH  Google Scholar 

  12. L. Kovács: On subgroups of the basic subgroup. Publ. Math. Debrecen 5 (1958), 261–264.

    MathSciNet  Google Scholar 

  13. W. May: The direct factor problem for modular abelian group algebras. Contemp. Math. 93 (1989), 303–308.

    MathSciNet  Google Scholar 

  14. W. May: Modular group algebras of simply presented abelian groups. Proc. Amer. Math. Soc. 104 (1988), 403–409.

    Article  MATH  MathSciNet  Google Scholar 

  15. N. Nachev: Basic subgroups of the group of normalized units in modular group rings. Houston J. Math. 22 (1996), 225–232.

    MATH  MathSciNet  Google Scholar 

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Danchev, P. Basic subgroups in modular abelian group algebras. Czech Math J 57, 173–182 (2007). https://doi.org/10.1007/s10587-007-0053-9

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  • DOI: https://doi.org/10.1007/s10587-007-0053-9

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