14,101 research outputs found
Connections between conjectures of Alon-Tarsi, Hadamard-Howe, and integrals over the special unitary group
We show the Alon-Tarsi conjecture on Latin squares is equivalent to a very
special case of a conjecture made independently by Hadamard and Howe, and to
the non-vanishing of some interesting integrals over SU(n). Our investigations
were motivated by geometric complexity theory.Comment: 7 page
Frequency permutation arrays
Motivated by recent interest in permutation arrays, we introduce and
investigate the more general concept of frequency permutation arrays (FPAs). An
FPA of length n=m lambda and distance d is a set T of multipermutations on a
multiset of m symbols, each repeated with frequency lambda, such that the
Hamming distance between any distinct x,y in T is at least d. Such arrays have
potential applications in powerline communication. In this paper, we establish
basic properties of FPAs, and provide direct constructions for FPAs using a
range of combinatorial objects, including polynomials over finite fields,
combinatorial designs, and codes. We also provide recursive constructions, and
give bounds for the maximum size of such arrays.Comment: To appear in Journal of Combinatorial Design
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