The known examples of embedded unitals (i.e. Hermitian arcs) in PG(2, q2) are B-unitals, i.e. they can be obtained from ovoids of PG(3, q) by a method due to Buekenhout. B-unitals arising from elliptic quadrics are called BM-unitals. Recently, BM-unitals have been classified and their collineation groups have been investigated. A new characterization is given in this paper. We also compute the linear collineation group fixing the B-unital arising from the Segre-Tits ovoid of PG(3, 2r), r ≥ 3 odd. It turns out that this group is an Abelian group of order q2.
A characterization of Buekenhout-Metz unitals in PG(2,q2), q even / Abatangelo, Vito; Larato, Bambina. - In: GEOMETRIAE DEDICATA. - ISSN 0046-5755. - STAMPA. - 59:2(1996), pp. 137-145. [10.1007/BF00155725]
A characterization of Buekenhout-Metz unitals in PG(2,q2), q even
Vito Abatangelo;Bambina Larato
1996-01-01
Abstract
The known examples of embedded unitals (i.e. Hermitian arcs) in PG(2, q2) are B-unitals, i.e. they can be obtained from ovoids of PG(3, q) by a method due to Buekenhout. B-unitals arising from elliptic quadrics are called BM-unitals. Recently, BM-unitals have been classified and their collineation groups have been investigated. A new characterization is given in this paper. We also compute the linear collineation group fixing the B-unital arising from the Segre-Tits ovoid of PG(3, 2r), r ≥ 3 odd. It turns out that this group is an Abelian group of order q2.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
