GraphTheory[SpecialGraphs]
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Calling Sequence
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PaleyGraph(p)
PaleyGraph(p,k)
PaleyGraph(p,k,m)
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Parameters
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p
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prime integer
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k
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positive integer
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m
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irreducible univariate polynomial of degree k over GF(p)
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Description
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If the input is PaleyGraph(p) where p is congruent to 1 modulo 4, then the output is an unweighted undirected graph G on p vertices labeled 0,1,...,p-1 where the edge {i,j}, with i<j, is in G iff j-i is a quadratic residue in Zp.
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If the input is PaleyGraph(p) where p is congruent to 3 modulo 4, then the output is an unweighted directed graph G on p vertices labeled 0,1,...,p-1 where the arc [i,j] is in G iff j-i is a quadratic residue in Zp.
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If the input is PaleyGraph(p,k) where is congruent to 1 modulo 4, then the output is an unweighted undirected graph G on vertices labeled 0,1,...,q-1 where the edge {i,j}, i<j, is in G iff y-x is a square in the finite field GF(q), where x is the th element and y is the th element in GF(q). The numbering of the elements in GF(q) is lexicographical.
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Similarly, if the input is PaleyGraph(p,k) where is congruent to 3 modulo 4, then the output is an unweighted directed graph G on vertices labeled 0,1,...,q-1 where the arc [i,j] is in G iff y-x is a square in the finite field GF(q), where x is the th element and y is the th element in GF(q). The numbering of the elements in GF(q) is lexicographical.
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The vertex label for the element f(x) in Zp[x] is f(p). For example, in GF(23) the elements are ordered . Thus the label for element is .
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The field can be specified by the user by specifying the extension polynomial for GF(q), a monic irreducible polynomial m(x) in Zp[x] of degree k.
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Examples
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