Fermi-LAT GeV excess and muon $g-2$ in a modular $A_4$ symmetry

Abstract: The recent measurement of muon anomalous magnetic dipole moment (muon $g-2$) suggests that there might exist new physics that dominantly interacts with muons. The observed gamma-ray excess from Fermi-LAT indicates that dark matter annihilates into a specific charged fermions. We propose a successful model simultaneously to explain the Fermi-LAT GeV gamma-ray excess and sizable muon $g-2$ with a modular $A_4$ symmetry. Due to nature of this symmetry, our DM only interacts with pairs of muon and we explain sizable muon $g-2$ without suffering from constraints of any lepton flavor violations. We numerically show our allowed spaces on each measurements of Fermi-LAT, relic density of DM and muon $g-2$, randomly scanning our input parameters.