Zee-Babu model in modular $A_4$ symmetry.

We study a Zee-Babu model in a modular $A_4$ flavor symmetry, in which we search for several predictions satisfying neutrino oscillation data. We perform $\Delta \chi^2$ analysis to get our results and find $\tau$ tends to be localized nearby at $2.3i$ for both of normal and inverted hierarchies, considering their theoretical origin.