Vol. 19, No. 1, 2021-2022

Download this article
Download this article For screen
For printing
Recent Issues
Volume 19, Issue 1
Volume 18, Issue 1
Volume 17, Issue 3
Volume 17, Issue 2
Volume 17, Issue 1
Volume 16, Issue 1
Volume 15, Issue 1
Volume 14, Issue 1
Volume 13, Issue 1
Volume 12, Issue 1
Volume 11, Issue 1
Volume 10, Issue 1
Volume 9, Issue 1
Volume 8, Issue 1
Volume 6+7, Issue 1
Volume 5, Issue 1
Volume 4, Issue 1
Volume 3, Issue 1
Volume 2, Issue 1
Volume 1, Issue 1
The Journal
About the Journal
Editorial Board
Subscriptions
 
Submission Guidelines
Submission Form
Policies for Authors
Ethics Statement
 
ISSN (electronic): 2640-7345
ISSN (print): 2640-7337
Author Index
To Appear
 
Other MSP Journals
Automorphisms of (affine) SL$(2,q)$-unitals

Verena Möhler

Vol. 19 (2021-2022), No. 1, 25–39
DOI: 10.2140/iig.2022.19.25
Abstract

SL((2,q)-unitals are unitals of order q admitting a regular action of SL((2,q) on the complement of some block. They can be obtained from affine SL((2,q)-unitals via parallelisms. We compute a sharp upper bound for automorphism groups of affine SL((2,q)-unitals and show that exactly two parallelisms are fixed by all automorphisms. In nonclassical SL((2,q)-unitals obtained as closures of affine SL((2,q)-unitals via those two parallelisms, we show that there is one block fixed under the full automorphism group.

Keywords
design, unital, affine unital, automorphism, parallelism
Mathematical Subject Classification
Primary: 51A10
Secondary: 05E18
Milestones
Received: 19 March 2021
Revised: 14 September 2021
Accepted: 2 November 2021
Published: 7 April 2022
Authors
Verena Möhler
Karlsruhe
Germany