On leptonic models for blazars in the Fermi era
  Some questions raised by Fermi-LAT data about blazars are summarized, along with attempts at solutions within the context of leptonic models. These include both spectral and statistical questions, including the origin of the GeV breaks in low-synchrotron peaked blazars, the location of the gamma-ray emission sites, the correlations in the spectral energy distributions with luminosity, and the difficulty of synchrotron/SSC models to fit the spectra of some TeV blazars. 
Charles Dermer (NRL) and Benoit Lott (Bordeaux)
astro-ph.HE astro-ph.CO