A Computer-Free Construction of the Third Group of Janko Original Research Article

We give a new constructive computer-free existence proof of the third group of Janko,J3, using the 9-dimensional unitary representation of 3J3overGF(4). Thereby we embed theC2.c-geometries for 3J3andJ3into the 9-dimensional unitary space and the 9-dimensional projective space, respectively.