Closedness of some subgroups in linear algebraic groups

On Closedness of Orbits of Algebraic Groups

Some good-filtration subgroups of simple algebraic groups

Let G be a connected and reductive algebraic group over an algebraically closed field of characteristic p > 0. An interesting class of representations of G consists of those G-modules having a good filtration – i.e. a filtration whose layers are the induced highest weight modules obtained as the space of global sections of G-linearized line bundles on the flag variety of G. Let H ⊂ G be a conne...

Finite Subgroups of Algebraic Groups

0. Introduction 1105 1. Constructible families 1111 2. Genericity for finite subgroups 1116 3. Finite groups of Lie type 1119 4. Basic nonconcentration estimate 1122 5. Finite subgroups of abelian varieties 1126 6. Orders of conjugacy classes and centralizers 1127 7. Regular semisimple and unipotent elements 1129 8. Minimal unipotent elements 1134 9. Frobenius map 1140 10. Traces in the basic c...

POS-groups with some cyclic Sylow subgroups

A finite group G is said to be a POS-group if for each x in G the cardinality of the set {y in G | o(y) = o(x)} is a divisor of the order of G. In this paper we study the structure of POS-groups with some cyclic Sylow subgroups.

Subgroups of Some Fuchsian Groups Defined by Two Linear Congruences

In this article we define a new family of subgroups of Fuchsian groups H( √ m), for a squarefree positive integer m, and calculate their index in H( √ m) and their parabolic class number. Moreover, we will show that the index of these subgroups is closely related to the solvability of a quadratic congruence x2 ≡ m(mod n) and the number of inequivalent solutions of a quadratic congruence x2 ≡ 1(...