Universe should be opaque to photons with energy TeV due scattering on the extragalactic background light during their propagation. However, a surprisingly high degree of transparency of the universe has been observed. In order to explain this fact, the conversion between photons and hypothetical axion-like particles in the turbulent extragalactic magnetic field has been invoked. We have derived new equations to calculate the mean survival probability of the photons. We have also found that the photon transfer functions on different lines of sight could have relevant deviations with respect to the mean value, producing both an enhancement or a suppression in the observable photon flux.
Photon-axion oscillations and the transparency of the universe
MONTANINO, Daniele
2011-01-01
Abstract
Universe should be opaque to photons with energy TeV due scattering on the extragalactic background light during their propagation. However, a surprisingly high degree of transparency of the universe has been observed. In order to explain this fact, the conversion between photons and hypothetical axion-like particles in the turbulent extragalactic magnetic field has been invoked. We have derived new equations to calculate the mean survival probability of the photons. We have also found that the photon transfer functions on different lines of sight could have relevant deviations with respect to the mean value, producing both an enhancement or a suppression in the observable photon flux.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
