Quasi-Two-Zero Texture in Type-II Seesaw at Fixed Points from Modular A 4 Symmetry
Takaaki Nomura, Hiroshi Okada · Progress of Theoretical and Experimental Physics · 2026
Abstract We study a quasi-two-zero neutrino texture based on a type-II seesaw model with modular $A_4$ symmetry to evade the cosmological bound on the sum of neutrino masses while keeping some predictability in the neutrino sector. Working on three fixed points for the modulus, we discuss predictions of the model and show the allowed points satisfying the cosmological bound on neutrino mass from both cosmic microwave background (CMB) and CMB + baryon acoustic oscillation data.