Global uniform in N estimates for solutions of a system of Hartree–Fock–Bogoliubov type in the Gross–Pitaveskii regime

abstract: We extend the recent work of Chong et al. (2022) to the critical case. More precisely, we prove global in time, uniform in $N$ estimates for the solutions $\phi$, $\Lambda$ and $\Gamma$ of a coupled system of Hartree--Fock--Bogoliubov type with interaction potential $\frac1NV_N(x-y)=N^{2}v(N(x-y))$. We assume that the potential $v$ is small which satisfies some technical conditions, and the initial conditions have finite energy. The main ingredient is a sharp estimate for the linear Schr"odinger equation with potential in 6+1 dimension, which may be of interest in its own right.