Expected high energy emission from GRB 080319B and origins of the GeV emission of GRBs 080514B, 080916C and 081024B

We calculate the high energy (sub-GeV to TeV) prompt and afterglow emission of GRB 080319B that was distinguished by a naked-eye optical flash and by an unusual strong early X-ray afterglow. There are three possible sources for high energy emission: the prompt optical and γ-ray photons IC scattered by the internal shock electrons, the prompt photons IC scattered by the early external reverse-forward shock electrons, and the higher band of the synchrotron and the synchrotron self-Compton emission of the external shock. There should have been in total ∼ 500 high energy photons detectable for the Large Area Telescope (LAT) onboard the Fermi satellite, and > 30 photons of those with energy > 10 GeV. The > 10 GeV emission had a duration about twice that of the soft γ-rays. AGILE could have observed these energetic signals if it was not occulted by the Earth at that moment. The physical origins of the high energy emission detected in GRB 080514B, GRB 080916C and GRB 081024B are also discussed. These observations can be reasonably interpreted by available high energy emission models based on our current understanding of GRBs and afterglows.