On the non-existence of generalized Hadamard matrices

Abstract It is shown that the solvability of certain quadratic forms is necessary for the existence of some generalized Hadamard matrices. The number-theoretic consequences of this are explored. In particular, non-existence results for generalized “Butson” Hadamard matrices BH(h,pf) and BH(h,2pf) are given, where p is a prime of the form 4k+3.