English

(Re)constructing Code Loops

Combinatorics 2021-09-24 v2 Group Theory

Abstract

The Moufang loop named for Richard Parker is a central extension of the extended binary Golay code. It the prototypical example of a general class of nonassociative structures known today as code loops, which have been studied from a number of different algebraic and combinatorial perspectives. This expository article aims to highlight an experimental approach to computing in code loops, by a combination of a small amount of precomputed information and making use of the rich identities that code loops' twisted cocycles satisfy. As a byproduct we demonstrate that one can reconstruct the multiplication in Parker's loop from a mere fragment of its twisted cocycle. We also give relatively large subspaces of the Golay code over which Parker's loop splits as a direct product.

Cite

@article{arxiv.1903.02748,
  title  = {(Re)constructing Code Loops},
  author = {Ben Nagy and David Michael Roberts},
  journal= {arXiv preprint arXiv:1903.02748},
  year   = {2021}
}

Comments

10 pages, three figures, one ancillary text file containing enough data to reconstruct the multiplication in the Parker loop. v2 Updated after referee feedback