Blow-up rate and local uniqueness for fractional Schr\"odinger equations with nearly critical growth

We study quantitative aspects and concentration phenomena for ground states of the following nonlocal Schr\"odinger equation $ (-\Delta)^s u+V(x)u= u^{2_s^*-1-\varepsilon} \ \ \text{in}\ \ \mathbb{R}^N, $ where $\varepsilon>0$, $s\in (0,1)$, $2^*_s:=\frac{2N}{N-2s}$, $N>4s$. We show that the ground state $u_{\varepsilon}$ blows up and precisely with the following rate $\|u_{\varepsilon}\|_{L^\infty(\mathbb{R}^N)}\sim \varepsilon^{-\frac{N-2s}{4s}}$, as $\epsilon\rightarrow 0^+$. We also localize the concentration points and, in the case of radial potentials $V$, we prove local uniqueness of sequences of ground states which exhibit a concentrating behavior.