On commutative semigroups which are unions of a finite number of principal ideals
On commutative subideal series of semigroups.
On commutative twisted group rings
Let be an abelian group, a commutative ring of prime characteristic with identity and a commutative twisted group ring of over . Suppose is a fixed prime, and are the -components of and of the unit group of , respectively. Let be the multiplicative group of and let be the -th Ulm-Kaplansky invariant of where is any ordinal. In the paper the invariants , , are calculated, provided . Further, a commutative ring with identity of prime characteristic is said...
On commuting elemts of groups acting on trees
On commuting generalized inverses in semigroups.
On compact Klein surfaces with a special automorphism group.
On compact -semigroups
On compact regular semigroups of complex matrices.
On complemented subgroups of finite groups
A subgroup of a group is said to be complemented in if there exists a subgroup of such that and . In this paper we determine the structure of finite groups with some complemented primary subgroups, and obtain some new results about -nilpotent groups.
On complete nilpotent groups.
On complete orbit spaces of SL(2) actions
On complete orbit spaces of SL(2) actions, II
The aim of this paper is to extend the results of [BB-Ś2] concerning geometric quotients of actions of SL(2) to the case of good quotients. Thus the results of the present paper can be applied to any action of SL(2) on a complete smooth algebraic variety, while the theorems proved in [BB-Ś2] concerned only special situations.
On complete -ideals in semigroups
On completely 0-simple semigroups.
On completely regular semigroups.
On composition factors of finite groups having the same set of element orders as the group .
On compressed ideals in topological semigroups
On computing quaternion quotient graphs for function fields
Let be a maximal -order in a division quaternion algebra over which is split at the place . The present article gives an algorithm to compute a fundamental domain for the action of the group of units on the Bruhat-Tits tree associated to . This action is a function field analog of the action of a co-compact Fuchsian group on the upper half plane. The algorithm also yields an explicit presentation of the group in terms of generators and relations. Moreover we determine an upper bound...
On conditionally commutative semigroups.
On congruence classes of -groups.