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binary Golay code (Definition)

The binary Golay Code $ \mathcal {G}_{23}$ is a perfect linear binary [23,12,7]-code with a plethora of different equivalent constructions.

Sample Constructions

  • Lexicographic Construction: Let $ v_0$ be the all-zero word in $ \mathbb{F}_2^{23}$, and inductively define $ v_j$ to be the smallest word (smallest with respect to the lexicographic ordering on $ \mathbb{F}_2^{23}$ that differs from $ v_i$ in at least 7 places for all $ i<j$.
  • Quadratic Residue Construction: $ \mathcal {G}_{23}$ is the quadratic residue code of length 23.

The extended binary Golay Code $ \mathcal {G}_{24}$ is obtained by appending a zero-sum check digit to the end of every word in $ \mathcal {G}_{23}$.

Both the binary Golay code and the extended binary Golay code have some remarkable properties.

Properties

  • $ \mathcal {G}_{24}$ has 4096 codewords: 1 of weight 0, 759 of weight 8, 2576 of weight 12, 759 of weight 18, and 1 of weight 24.
  • The automorphism group of $ \mathcal {G}_{24}$ is the Mathieu group $ M_{24}$, one of the sporadic groups.
  • The Golay Code is used to define the Leech Lattice, one of the most efficient sphere-packings known to date.
  • The optimal strategy to the mathematical game called Mogul is to always revert the current position to one corresponding to a word of the Golay code.
  • The words of weight 8 in $ \mathcal {G}_{24}$ form a $ S(5,8,24)$ Steiner system. In fact, this property uniquely determines the code.



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Also defines:  extended binary golay code
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Cross-references: property, Steiner system, current, game, strategy, lattice, group, automorphism group, weight, digit, length, code, quadratic residue, places, lexicographic ordering, binary, perfect
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This is version 1 of binary Golay code, born on 2004-06-04.
Object id is 5891, canonical name is BinaryGolayCode.
Accessed 5167 times total.

Classification:
AMS MSC11T71 (Number theory :: Finite fields and commutative rings :: Algebraic coding theory; cryptography)

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