The 2A-Majorana representations of the Harada-Norton group

Clara Franchi, Alexander A. Ivanov, Mario Mainardis


We show that all 2A-Majorana representations of the Harada-Norton group F5 have the same shape. If R is such a representation, we determine, using the theory of association schemes, the dimension and the irreducible constituents of the linear span U of the Majorana axes. Finally, we prove that, if R is based on the (unique) embedding of F5 in the Monster, U is closed under the algebra product.


Majorana representations, association schemes, Monster algebra, Harada-Norton group

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ISSN: 1855-3974

Issues from Vol 6, No 1 onward are partially supported by the Slovenian Research Agency from the Call for co-financing of scientific periodical publications