Abstract
We give a characterization of the Buekenhout-Metz unitals in PG(2, q 2), in the cases that q is even or q=3, in terms of the secant lines through a single point of the unital. With the addition of extra conditions, we obtain further characterizations of Buekenhout-Metz unitals in PG(2, q 2), for all q. As an application, we show that the dual of a Buekenhout-Metz unital in PG(2, q 2) is a Buekenhout-Metz unital.
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Casse, L.R.A., O'Keefe, C.M. & Penttila, T. Characterizations of Buekenhout-Metz unitals. Geom Dedicata 59, 29–42 (1996). https://doi.org/10.1007/BF00181524
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DOI: https://doi.org/10.1007/BF00181524