Characterizing the Hermitian and Ree unitals on 28 points
We prove a conjecture of Brouwer, namely that a 2-(28,4,1) design has 2–rank at least 19, with equality occuring if and only if the design is the Ree unital. We give a similar characterization of the Hermitian unital.
Designs, Codes and Cryptography
Characterizing the Hermitian and Ree unitals on 28 points.
Designs, Codes and Cryptography,
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