Asymptotic profiles for Choquard equations with general critical nonlinearities

In this paper, we study asymptotic behavior of positive ground state solutions for the nonlinear Choquard equation: \begin{equation}\label{0.1} -Δu+\varepsilon u=\big(I_α\ast F(u)\big)F’(u),\quad u\in H^1(\mathbb R^N), \end{equation} where $F(u)=\mathrm{\mid }u{\mathrm{\mid }}^{\frac{N+\alpha }{N-2}}+G(u)$, $N\ge 3$ is an integer, $I_{\alpha }$ is the Riesz potential of order $\alpha \in (0,N)$, and $\epsilon >0$ is a parameter. Under some mild subcritical growth assumptions on $G(u)$, we show that as $\epsilon \to \mathrm{\infty }$, the ground state solutions of \eqref{0.1}, after a suitable rescaling, converge to a particular solution of the critical Choquard equation $-\mathrm{\Delta }u=\frac{N+\alpha }{N-2}(I_{\alpha }\ast \mathrm{\mid }u{\mathrm{\mid }}^{\frac{N+\alpha }{N-2}})\mathrm{\mid }u{\mathrm{\mid }}^{\frac{N+\alpha }{N-2}-2}u$. We establish a novel sharp asymptotic characterisation of such a rescaling, which depends in a non-trivial way on the asymptotic behavior of $G(u)$ at infinity and the space dimension $N=3$, $N=4$ or $N\ge 5$.