Speaker: Guillermo Carlo Nuñez (WPI)
Title: "Nonexistence of quaternary unit Hadamard matrices"
Abstract: Quaternary unit Hadamard matrices are a family of complex Hadamard matrices with entries in a biquadratic extension of the rationals. We obtain nonexistence conditions for this family of matrices by studying prime ideal factorization on biquadratic number fields. Our approach generalizes the nonexistence results of Butson Hadamard matrices by Winterhof. This is joint work with Padraig Ó Catháin, Philip Heikoop and John Pugmire.