On -hyperelliptic involutions of Riemann surfaces.
On pq-hyperelliptic Riemann surfaces
A compact Riemann surface X of genus g > 1 is said to be p-hyperelliptic if X admits a conformal involution ϱ, called a p-hyperelliptic involution, for which X/ϱ is an orbifold of genus p. If in addition X admits a q-hypereliptic involution then we say that X is pq-hyperelliptic. We give a necessary and sufficient condition on p,q and g for existence of a pq-hyperelliptic Riemann surface of genus g. Moreover we give some conditions under which p- and q-hyperelliptic involutions of a pq-hyperelliptic...
On Schur-Ostrowski type theorems for group majorizations.
On soluble groups of module automorphisms of finite rank
Let be a commutative ring, an -module and a group of -automorphisms of , usually with some sort of rank restriction on . We study the transfer of hypotheses between and such as Noetherian or having finite composition length. In this we extend recent work of Dixon, Kurdachenko and Otal and of Kurdachenko, Subbotin and Chupordia. For example, suppose is -Noetherian. If has finite rank, then also is -Noetherian. Further, if is -Noetherian and if only certain abelian sections...
On some infinite dimensional linear groups
Let F be a field, A be a vector space over F, and GL(F,A) the group of all automorphisms of the vector space A. A subspace B of A is called nearly G-invariant, if dimF(BFG/B) is finite. A subspace B is called almost G-invariant, if dimF(B/CoreG(B)) is finite. In the present article we begin the study of subgroups G of GL(F,A) such that every subspace of A is either nearly G-invariant or almost G-invariant. More precisely, we consider the case when G is a periodic p′-group where p = charF.
On Spaces of Kleinian Groups
On subgroups of GL (n, A) which are generated by commutators. II.
On Subgroups of GL(n, A) which Are Generated by Commutators.
On subgroups of GLn (Fp).
On subgroups of the general linear group over the skew field of quaternions which contain the symplectic group.
On subnormal subgroups of linear groups.
On suborbital graphs for the normalizer of .
On supersoluble groups acting on Klein surfaces.
On symplectic groups over polynomial rings.
On the Albanese variety of the moduli space of polarized K3 surfaces.
On the automorphism group of a toroidal hypermap
On the congruence subgroup problem, II.
On the Congruence Subgroups Problem: Determination of the "Metaplectic Kernel".
On the congruence-subgroup problem for some anisotropic algebraic groups over number fields.
On the connectedness of the locus of real Riemann surfaces.