6.2.5. Ghirlanda or *E* <sup>p</sup>–*E<sup>γ</sup>* Correlation

This represents a tight, less scattered, correlation between *E*<sup>p</sup> and *Eγ*, valid for LGRBs [134]. One of the major drawbacks is the lack of achromatic breaks in the *Swift* afterglow light curves of most of the GRBs. This fact limits the increase in the correlation sample. For details, see Ref. [130].
