A note on the predictions of models with modular flavor symmetries

Models with modular flavor symmetries have been thought to be highly predictive. We point out that these predictions are subject to corrections from non-holomorphic terms in the Lagrangean. Specifically, in the models discussed in the literature, the Kahler potential is not fixed by the symmetries, for instance. The most general Kahler potential consistent with the symmetries of the model contains additional terms with additional parameters, which reduce the predictive power of these constructions. We also comment on potential ways of how one may conceivably retain the predictivity. (C) 2019 The Authors. Published by Elsevier B.V.