Modular plethystic isomorphisms for two-dimensional linear groups

Two-dimensional Projective Linear Groups

This article is a contribution to the study of the automorphism groups of 2 − (v, k, 1) designs. Let G act as a block-transitive and point-primitive automorphism group of a non-trivial design D with v points and blocks of size k. Set k2 = (k, v−1). Assume q = pf for some prime p and positive integer f . If q ≥ [(k2k − k2 + 1)f ]2, then Soc(G), the socle of G, is not PSL(2, q). Mathematics Subje...

On the Isomorphisms of Two Metacyclic Groups

Classical Isomorphisms for Quantum Groups

The expressions for the R̂–matrices for the quantum groups SOq2(5) and SOq(6) in terms of the R̂–matrices for Spq(2) and SLq(4) are found, and the local isomorphisms of the corresponding quantum groups are established. On leave of absence from P.N.Lebedev Physical Institute, Theoretical Department, 117924 Moscow, Leninsky prospect 53, CIS.

Isomorphisms of Groups

Definition: If (G, *) and (H, •) are groups, then a function f : G −→ H is a homomorphism if f (x * y) = f (x) • f (y) for all x, y ∈ G. Example: Let (G, *) be an arbitrary group and H = {e}, then the function f : G −→ H such that f (x) = e for any x ∈ G is a homomorphism. In fact, f (x * y) = e = e • e = f (x) • f (y).

Isomorphisms of Graph Groups

Given a graph X, define the presentation PX to have generators the vertices of X, and a relation xy = yx for each pair x, y of adjacent vertices. Let GX be the group with presentation PX, and given a field K, let KX denote the K"-algebra with presentation PX. Given graphs X and Y and a field K, it is known that the algebras KX and KY are isomorphic if and only if the graphs X and Y are isomorph...