Uniform in $N$ estimates for a Bosonic system of Hartree-Fock-Bogoliubov type

Abstract

We prove local 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 $v_N(x-y) =N^{3 \beta} v(N^{\beta}(x-y))$, with $\beta <1$ and $v$ a Schwartz function (satisfying additional technical requirements). The initial conditions are general functions in a Sobolev-type space, and the expected correlations in $\Lambda$ develop dynamically in time. As shown in our previous work, as well as the work of J. Chong, (both in the case $\beta<2/3$), using the conserved quantities of the system of equations, this type of local in time estimates can be extended globally. Also, they can be used to derive Fock space estimates for the approximation of the exact evolution of a Bosonic system by states of the form $e^{\sqrt N A(\phi)}e^{B(k)} \Omega$. This will be addressed in detail in future work.