The Translation Planes of Order 16 That Admit PSL(2, 7)

Publisher Summary A translation plane of order 16 admits SL (2, 4) as a collineation group of the translation complement if and only if Π is Desarguesian, Hall, or Dempwolff. Because there are only seventeen points on the line at infinity, users may complete the roof of the main result by combinatorial arguments. An alternate approach would be to compute the possible GF (2) SL(2, 4) modules and use representation theory. A Sylow 2-subgroup fixes exactly two points of the orbit of length 10 and clearly no two Sylow 2-subgroups can fix a common point in this orbit.