Primitive block designs with automorphism group PSL(2,Q)

Snježana Braić, Joško Mandić, Tanja Vučičić
2015 Glasnik Matematicki - Serija III  
We present the results of a research which aims to determine, up to isomorphism and complementation, all primitive block designs with the projective line Fq ∪ {∞} as the set of points and PSL (2, q) as an automorphism group. The obtained designs are classified by the type of a block stabilizer. The results are complete, except for the designs with block stabilizers in the fifth Aschbacher's class. In particular, the problem is solved if q is a prime. We include formulas for the number of such
more » ... he number of such designs with q = p 2 α 3 β , α, β nonnegative integers. 2010 Mathematics Subject Classification. 05B05.
doi:10.3336/gm.50.1.01 fatcat:73xmzdhprbenvmncq7bnokjwee