We study the modular symmetry in magnetized D-brane models on T2. Non-Abelian flavor symmetry D4 in the model with magnetic flux M=2 (in a certain unit) is a subgroup of the modular symmetry. We also study the modular symmetry in heterotic orbifold models. The T2/Z4 orbifold model has the same modular symmetry as the magnetized brane model with M=2, and its flavor symmetry D4 is a subgroup of the modular symmetry.
@article{arxiv.1804.06644,
title = {Modular symmetry and non-Abelian discrete flavor symmetries in string compactification},
author = {Tatsuo Kobayashi and Satoshi Nagamoto and Shintaro Takada and Shio Tamba and Takuya H. Tatsuishi},
journal= {arXiv preprint arXiv:1804.06644},
year = {2018}
}