Ground states for the Hartree energy functional in the critical case
Tommaso Pistillo
TL;DR
This work analyzes the Hartree energy functional in $\mathbb{R}^3$ with convolution potentials in $L^\infty+L^{3/2,\infty}$, allowing for attractive, long-range interactions including Coulomb-type and inverse-power potentials. By combining Lorentz-space estimates with a refined concentration-compactness framework, the authors prove the existence of ground states for a large mass range, establish positivity and regularity, and derive the Euler–Lagrange equation and enhanced regularity results. They then study the associated time-dependent Hartree equation, proving global well-posedness under a smallness condition and orbital stability of the ground-state set, thereby linking variational structures to dynamical behavior. These results broaden the class of admissible potentials and provide a robust variational-dynamical theory for nonlocal nonlinear Schrödinger-type equations.
Abstract
We consider the problem of finding a minimizer $u$ in $ H^1(\mathbb{R}^3)$ for the Hartree energy functional with convolution potential $w$ in $L^\infty(\mathbb{R}^3)+L^{3/2,\infty}(\mathbb{R}^3)$ with $L^\infty$ part vanishing at infinity. This class includes sums of potentials of the kind $-\frac{1}{|x|^α}$, $0<α\le2$, together with the case $w$ in $L^{3/2}(\mathbb{R}^3)$. We prove the existence of such groundstates for a wide range of $L^2$ masses. We also establish basic properties of the groundstates, i.e.~positivity and regularity. Lastly, we exploit the estimates we derived for the stationary problem to prove global well-posedness of the associated evolution problem and orbital stability of the set of ground states.
