Gravitational wave signatures from discrete flavor symmetries

Non-Abelian discrete symmetries have been widely used to explain the patterns of lepton masses and flavor mixing. In these models, a given symmetry is assumed at high scale then spontaneously broken by scalars (the flavons), which acquire vacuum expectation values. Typically, resulting leading order predictions for oscillation parameters require corrections in comply with neutrino data. We introduce such through an explicit small breaking symmetry. This has advantage solving cosmological problems models without resorting inflation. The induces energy difference or "bias" between different vacua drives evolution domain walls, unavoidably produced after breaking, towards their annihilation. Importantly, wall annihilation leads gravitational waves may be observed current and/or future experiments. show that distinctive pattern multiple overlapped peaks generated when walls annihilate, within reach detectors. also cosmic from can cosmologically safe any spontaneous 1 $10^{18}$ GeV, if bias chosen adequately, need inflate away. use as example particular $A_4$ model included right-handed mass terms.