Phase transitions of the electron fluid

We demonstrate that current many-body theory predicts that the high-density phase of the electron fluid is mechanically unstable for rs greater, similar 5 and thermo-dynamically unstable for rs greater, similar 4. The pressure-density phase diagram of the electron fluid is shown to consist of a high-density, liquid-like region and a low-density, gas-like region, separated by a two-phase region. We calculate the low-density segment of the coexistence curve in the limit of low temperature and pressure.