On the Mathieu group M23

Maximal Subgroups of the Mathieu Group M23 and Symplectic Automorphisms of Supersingular K3 Surfaces

We show that the Mathieu groups M22 and M11 can act on the supersingular K3 surface with Artin invariant 1 in characteristic 11 as symplectic automorphisms. More generally we show that all maximal subgroups of the Mathieu group M23 with three orbits on 24 letters act on a supersingular K3 surface with Artin invariant 1 in a suitable characteristic.

Decoding the Mathieu Group

The sporadic Mathieu group M12 can be viewed as an errorcorrecting code, where the codewords are the group’s elements written as permutations in list form, and with the usual Hamming distance. We investigate the properties of this group as a code, in particular determining completely the probabilities of successful and ambiguous decoding of words with more than 3 errors (which is the number tha...

Decoding the Mathieu group M12

We show how to use the elements of a sharply k-transitive permutation group of degree n to form error-correcting codes, as suggested by Blake [1], presenting suitable decoding algorithms for these codes. In particular, we concentrate on using the Mathieu group M12 to form a (12,95040,8)-code to correct three errors. The algorithm we give for this code differs from that given by Cohen and Deza [2].

The 3-local cohomology of the Mathieu group M24

The Mathieu group M12 and its pseudogroup extension M13, Experiment

We study a construction of the Mathieu group M12 using a game reminiscent of Loyd’s “15-puzzle”. The elements of M12 are realized as permutations on 12 of the 13 points of the finite projective plane of order 3. There is a natural extension to a “pseudogroup” M13 acting on all 13 points, which exhibits a limited form of sextuple transitivity. Another corollary of the construction is a metric, a...