English

Parallelisms and Translations of (Affine) SL(2,q)-Unitals

Combinatorics 2020-12-22 v2

Abstract

Unitals can be obtained as closures of affine unitals via parallelisms. The isomorphism type of the closure depends on the chosen parallelism, which need not be unique. For affine SL(2,q)\operatorname{SL}(2,q)-unitals, we introduce a class of parallelisms for odd order and one for square order. Translations are automorphisms of unitals, fixing each block through a given center. For each of the known parallelisms of affine SL(2,q)\operatorname{SL}(2,q)-unitals, we compute all possible translations with centers on the block at infinity.

Keywords

Cite

@article{arxiv.2012.10129,
  title  = {Parallelisms and Translations of (Affine) SL(2,q)-Unitals},
  author = {Verena Möhler},
  journal= {arXiv preprint arXiv:2012.10129},
  year   = {2020}
}

Comments

16 pages; references updated. arXiv admin note: text overlap with arXiv:2012.10116