I think they are flying blind here. Too much is not known about the sources of Gamma Rays to run very far with this. As Neried observed in the abstract the authors caution, "We cannot exclude the possibility that the delay we find, which is significant beyond the 95% C.L., may be due to some energy-dependent effect at the source."

The authors are looking at one of many possible reasons the energy peaks in different wavelengths at different times. Without a good physical mechanism that explains exactly how theses events originate, it is difficult to weigh-in on how the energy should be expected to be distributed.

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jwj

It's a big universe out there...is it really unwinding, really burning out?