The anisotropic distribution of the interacting electrons
arXiv:1301.4711
Abstract
The distribution function for a system of interacting electrons in metals is multivalent in a certain region of wave vectors. One solution among many is isotropic. For other solutions the distribution of electrons over the wave vectors is anisotropic. In the simplest case, the anisotropy arises as a result of the repulsion between electrons in states with the wave vectors and $-\hh\bf k$.
11 pages