W. Arveson has described a cocycle conjugacy class U(α) of E0-semigroup α on B(H) which is a factor of type I. Under some conditions on α there is a E0-semigroup β ∈ U(α) being a flow of shifts in the sense of R.T.Powers (see [11]). We study quasifree endomorphisms semigroups α on the hyperfinite factor M = π(A(K)) generated by the representation π of the algebra of the canonical anticommutatio...

The Fischer group Fi22 acts as a rank 3 group of automorphisms of a symmetric 2-(14080,1444,148) design. This design does not have a doubly transitive automorphism group, since there is a partial linear space with lines of size 4 defined combinatorially from the design and preserved by its automorphism group. We investigate this geometry and determine the structure of various subspaces of it. I...