Representations of \(SL(2,4)\) on translation planes of even order (Q790419)

Dempwolff has constructed a translation plane of order 16 admitting \(SL(2,4)\). (Dempwolff's result still seems to be unpublished). This showed that a result of Johnson and the reviewer about translation planes of even order admitting \(SL(2,2^ s)\) was incorrect unless the condition \(s>2\) is added [Geom. Ded. 8, 39-60, (1979; Zbl 0403.51004)]. The author gives a group theoretic construction of the Dempwolff plane and shows that it is derived from a semifield of order 16 and kernel \(GF(2)\).