Designs, Codes and Cryptography

, Volume 60, Issue 2, pp 197–201 | Cite as

Non-Existence of isomorphisms between certain unitals

  • Theo Grundhöfer
  • Boris Krinn
  • Markus Stroppel


We show that the Ree-Tits unitals are neither classical nor isomorphic to the polar unitals found in the Coulter-Matthews planes. To this end, we determine the full automorphism groups of the finite Ree-Tits unitals.


Unital Ree group Coulter–Matthews plane Isomorphism Automorphism group O’Nan configuration 

Mathematics Subject Classification (2000)

Primary 05E20 Secondary 51A10 51E26 51D20 05B05 


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Theo Grundhöfer
    • 1
  • Boris Krinn
    • 2
  • Markus Stroppel
    • 3
  1. 1.Institut für MathematikUniversität WürzburgWürzburgGermany
  2. 2.Institut für Geometrie und TopologieUniversität StuttgartStuttgartGermany
  3. 3.Fachbereich MathematikUniversität StuttgartStuttgartGermany

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