Axion mechanism of Sun luminosity, dark matter and extragalactic background light

Abstract: We show the existence of the strong inverse correlation between the temporal variations of the toroidal component of the magnetic field in the solar tachocline (the bottom of the convective zone) and the Earth magnetic field (the Y-component). The possibility that the hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of the Sun convective zone modulates the magnetic field of the Earth is considered. We propose the axion mechanism of Sun luminosity and "solar dynamo -- geodynamo" connection, where the energy of one of the solar axion flux components emitted in M1 transition in 57Fe nuclei is modulated at first by the magnetic field of the solar tachocline zone (due to the inverse coherent Primakoff effect) and after that is resonantly absorbed in the core of the Earth, thereby playing the role of the energy modulator of the Earth magnetic field. Within the framework of this mechanism estimations of the strength of the axion coupling to a photon (g_{a \gamma} = 7.07e-11 1/GeV), the axion-nucleon coupling (g_{an} = 3.20e-7), the axion-electron coupling (g_{ae} = 5.28e-11) and the axion mass (m_a = 17eV) have been obtained. It is also shown that the claimed axion parameters do not contradict to any known experimental and theoretical model-independent limitations. We consider the effect of dark matter in the form of 17eV axions on the extragalactic back-ground light (EBL) and find that the theoretical spectral intensity of the EBL from decaying axions as a function of the observed wavelength is in good agreement with the known experimental data for the near ultraviolet, optical and near infrared bands (1500-20000 angstrom).