 Gravitational Hartree equation

The Gravitational Hartree equation couples a complex wave function to the attractive Newtonian gravitational potential generated by its own squared modulus. In dimension $N\ge 3$, a dimensionless convention iswhere $C_N=(N-2)|S^{N-1}|$ and $|S^{N-1}|$ is the area of the unit sphere. The minus sign in the fundamental solution makes $\varphi \le 0$ for nonnegative density, with the potential selected to decay at infinity when the convolution permits it.

The convolution makes the nonlinearity nonlocal: changing the density at one point changes the potential elsewhere. The Newtonian kernel and its dimension differ from a local cubic nonlinear Schrödinger equation. In three dimensions, the Hardy–Littlewood–Sobolev inequality controls the interaction energy and leads to Global H1 solutions of the three-dimensional gravitational Hartree equation.