On abelian schemes
نویسنده
چکیده
Let P = fP0; :::; Png be a partition of a nite abelian group A and L(P ) the complex vector space generated by the indicator functions of the sets P0; :::; Pn. In [1] it was proved that P de nes an abelian association scheme on A if L(P ) equals the space L(P ) of all Fourier transforms of functions in L(P ). In this paper it is shown that P de nes an abelian association scheme on A if and only if L(P ) = L(Q) for some partition Q of A. Also, several examples illustrating the above result are given.
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