A Block Negacyclic Bush-Type Hadamard Matrix and Two Strongly Regular Graphs
نویسندگان
چکیده
منابع مشابه
A Block Negacyclic Bush-Type Hadamard Matrix and Two Strongly Regular Graphs
A block negacyclic Bush-type Hadamard matrix of order 36 is used in a symmetric BGW(26, 25, 24) with zero diagonal over a cyclic group of order 12 to construct a twin strongly regular graph with parameters v=936, k=375, l=m=150 whose points can be partitioned in 26 cocliques of size 36. The same Hadamard matrix then is used in a symmetric BGW(50, 49, 48) with zero diagonal over a cyclic group o...
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(otherwise we divide the vector by an appropriate scalar), so w.l.o.g. we have uj = 1 for a certain j ∈ {1, . . . , v}. The absolute value |(A~u)j| of the j-th component of A~u is at most ∑ i∼j |ui|; since the absolute values of all components of ~u are less than or equal to 1, we have ∑ i∼j |ui| ≤ k. On the other hand |(A~u)j| must be equal to |ρuj| = |ρ|, from which we obtain |ρ| ≤ k. If ρ = ...
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ژورنال
عنوان ژورنال: Journal of Combinatorial Theory, Series A
سال: 2002
ISSN: 0097-3165
DOI: 10.1006/jcta.2001.3231