© 1997 by London Mathematical Society
© The London Mathematical Society
Two New Constructions of the O'Nan Group
Lehrstuhl D für Mathematik RWTH Aachen Germany
School of Mathematics & Statistics, University of Birmingham Birmingham B15 2TT
Received 2 May 1995.
A construction is described of a 153-dimensional representation of the triple cover of O'Nan's sporadic simple group, over the field of order 4. This is then extended to a 306-dimensional representation of 3·O'N:2 over GF(2). A similar construction in characteristic 3 gives an unrelated representation of the O'Nan group in 154 dimensions over GF(3), which extends to O'N:2 provided that the field is extended to GF(9).