Gamma-ray flare and absorption in Crab Nebula: Lovely TeV-PeV
  astrophysics
  We spectrally fit the GeV gamma-ray flares recently-observed in the Crab
Nebula by considering a small blob Lorentz-boosted towards us. We point out
that the corresponding inverse-Compton flare at TeV--PeV region is more
enhanced than synchrotron by a Lorentz factor square \sim \Gamma^2, which is
already excluding \Gamma \gtrsim 200 and will be detected by future TeV - PeV
observatories, CTA, Tibet AS + MD and LHAASO for \Gamma \gtrsim 30. We also
show that PeV photons emitted from the Crab Nebula are absorbed by Cosmic
Microwave Background radiation through electron-positron pair creation.
