In this paper, we establish the asymptotic behavior of supercritical nearly unstable Hawkes processes with a power law kernel. We find that, the Hawkes process in our context admits a similar equation to that in MR3563196 for subcritical case. In particular, the rescaled Hawkes process (Zⁿ₍ₓ/n^2) ₓ₀, ₁ converges in law to a kind of integrated fractional Cox Ingersoll Ross process with different coefficients from that in MR3563196, as n tends to infinity.
Xu et al. (Wed,) studied this question.