In this paper, we prove that maximal (k, 2)-arcs in projective Hjelmslev planes over chain rings R of nilpotency index 2 exist if and only if charR = 4. © 2005 Elsevier Inc. All rights reserved.

In this paper, we completely determine the point regular automorphism groups of Payne derived quadrangle symplectic W(q), q odd. As a corollary, show that finite act regularly on points generalized can have unbounded nilpotency class.

We show nilpotency and completeness results for the homotopy automorphisms of a marked n-stage an unstable coalgebra. These objects figure in moduli problem coalgebras. Our theorems extend classical work Dror, Zabrodsky, Maruyama Møller.

in this paper‎, ‎we give a complete proof of theorem 4.1(ii) and a new‎ ‎elementary proof of theorem 4.1(i) in [li and shen‎, ‎on the‎ ‎intersection of the normalizers of the derived subgroups of all‎ ‎subgroups of a finite group‎, ‎ j‎. ‎algebra, ‎323  (2010) 1349--1357]‎. ‎in addition‎, ‎we also give a generalization of baer's theorem‎.

IN this paper we shall study the connection between local and global nilpotency for groups which satisfy certain chain conditions. In the first section, we shall prove that a group satisfying the chain condition on centralizers has a unique maximal normal nilpotent subgroup (the Fitting subgroup), i.e. the group generated by all normal nilpotent subgroups must again be nilpotent. This generaliz...